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Enhancements of electrical properties and positive bias instability in self-aligned top-gate a-IGZO TFTs by hydrogen incorporation Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-25 Yuan-Ming Liu, Jih-Chao Chiu, Yu-Ciao Chen, Yu-Cheng Fan, Rong-Wei Ma, Chia-Chun Yen, Tsang-Long Chen, Cheng-Hsu Chou, C W Liu
Flow rate effects of the silane (SiH4) and ammonia (NH3) on the top gate insulator and the cap layer in self-aligned top-gate amorphous InGaZnO thin film transistors are investigated. The hydrogen density increases with increasing SiH4 and NH3 flow rates. Hydrogen passivation can improve the field-effect mobility, subthreshold swing (S.S.), hysteresis. The positive bias instability is also improved
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Performance improvement of enhancement-mode GaN-based HEMT power devices by employing a vertical gate structure and composite interlayers* Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-25 Zhonghao Sun, Jianxun Dai, Huolin Huang, Nan Sun, Jiayu Zhang, Yun Lei, Dawei Li, Kaiming Ma, Huimin Yu, Yanhong Liu, Hui Huang, Yung C Liang
In this work, p-n junction vertical gate (JVG) and polarization junction vertical gate (PVG) structures are for the first time proposed to improve the performance of GaN-based enhancement-mode (E-mode) high electron mobility transistor (HEMT) devices. Compared with the control group featuring the vertical gate structure, a highly improved threshold voltage (V th) and breakdown voltage (BV) are achieved
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Computing in-memory reconfigurable (accurate/approximate) adder design with negative capacitance FET 6T-SRAM for energy efficient AI edge devices Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-21 Birudu Venu, Tirumalarao Kadiyam, Koteswararao Penumalli, Sivasankar Yellampalli, Ramesh Vaddi
Computing in-memory (CiM) is an alternative to von-Neumann architectures for energy efficient AI edge computing architectures with CMOS scaling. Approximate computing in-memory (ACiM) techniques have also been recently proposed to further increase the energy efficiency of such architectures. In the first part of the work, a negative capacitance FET (NCFET) based 6T-SRAM CiM accurate full adder has
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Effect of two-dimensional non-local screening on characteristics of transition metal dichalcogenide monolayers Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-20 Vram Mughnetsyan, Aram Manaselyan, Ashot Movsisyan, Albert Kirakosyan
On the basis of the theory developed for the dielectric function of atomic thin layer insulating materials (Cudazzo et al 2011 Phys. Rev. B 84 085406), some characteristics of transition metal dichalcogenide monolayers are calculated in the framework of variational method. This method initially was designed to work for very weak or strong magnetic fields, but it is also in very good agreement with
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Simultaneous enhancements on emissions from quantum dot and quantum well by Ag nanoparticles for color conversion Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-20 C H Deng, Z Z Chen, Y F Chen, Q Sun, J X Nie, Z J Pan, H D Zhang, B Y Dong, Y A Chen, D Q Wang, Y C Li, W H Chen, X N Kang, Q Wang, G Y Zhang, B Shen, H J Wang, F Wang, W Wang, Z X Li
Quantum dots (QDs) have been paid much attention on the color conversion for light-emitting diode (LED) in micro-display recently. However, it is hard to achieve high color conversion efficiency in a thin QD layer. In this paper, we fabricated silver nanoparticles (Ag NPs) with radii ranging mostly from 25 to 35 nm on a blue LED with a peak wavelength of 450 nm, then spin-coated QDs with a peak wavelength
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Normally-off GaON/p-GaN gate HEMTs with selective plasma oxidation: from structural characterization, performance improvement to physical mechanism Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-18 Nengtao Wu, Zhiheng Xing, Ling Luo, Guoqiang Li
In this letter, a p-GaN gate high-electron-mobility transistor (HEMT) with a high threshold voltage and better gate reliability was demonstrated by using selective plasma oxidation (SPO) and an additional low-temperature annealing step before gate metal is evaporated. After the SPO, a gallium oxynitride (GaON) dielectric layer was formed on the surface of p-GaN under the gate metal, and was studied
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Electronic transport properties of WS2 using ensemble Monte Carlo method Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-14 M Derya Alyörük
The electronic transport characteristics of tungsten disulfide (WS2) sheets are studied using the ensemble Monte Carlo technique in the presence of intrinsic scattering mechanisms only. The transport properties of the material are obtained in a two-valley model where intra- and inter-valley scatterings are considered in K and Q valleys. The velocity overshoot effect is observed for some applied field
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Flexible field-effect transistors with high-quality and uniform single-layer graphene for high mobility Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-13 Hyunjin Park, Jimin Kwon, Jihyung Seo, Kiho Kim, Yun Ho Kim, Sungjune Jung
In this work, a fully flexible graphene field-effect transistor with high carrier mobility is reported. Patterned high-quality and uniform single-layer graphene films are successfully realized by combining the selective growth on a patterned copper foil and the direct transfer method to minimize degradation factors. The selectively grown single-layer graphene is directly transferred to the target substrate
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Influence of halogen precursors on the growth of InSb nanostructures Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-12 Alexander K Sten, Kevin M Roccapriore, Brian Squires, Chris Littler, A J Syllaios, Usha Philipose
The present work highlights the role of halogen compounds in modifying the shape of the InSb nanostructures, while maintaining a high crystalline quality of the nanostructures. One-dimensional (1D) nanowires (NWs) and two-dimensional (2D) nanoplatelets (NPLs) were synthesized by ambient pressure chemical vapor deposition. Our experimental results suggest that at a critical growth temperature of 512
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Insights into dynamic switching behavior and electric field distribution of depletion-mode GaN HEMT with bonding pad over active layout Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-08 Lijian Guo, Feng Zhou, Weizong Xu, Fangfang Ren, Dong Zhou, Dunjun Chen, Rong Zhang, Youdou Zheng, Hai Lu
Bonding pad over active (BPOA) layout, which stacks traditional horizontal structure pad electrodes vertically above the active area, is an area-effective device architecture and packaging-enabled solution for GaN-based high electron mobility transistors (HEMTs). In this work, the dynamic switching and electric field distribution of such layout, as well as associated capacitance–voltage and trapping
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Improved resistive switching characteristics of solution processed ZrO2/SnO2 bilayer RRAM via oxygen vacancy differential Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-08 Kihwan Choi, James Jungho Pak
In this study, a solution-processed bilayer structure ZrO2/SnO2 resistive switching (RS) random access memory (RRAM) is presented for the first time. The precursors of SnO2 and ZrO2 are Tin(Ⅱ) acetylacetonate (Sn(AcAc)2) and zirconium acetylacetonate (Zr(C5H7O2)4), respectively. The top electrode was deposited with Ti using an E-beam evaporator, and the bottom electrode used an indium–tin–oxide glass
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Study on low-temperature evaporation of Ag2O-based Ag electrode and electron injection layer and their application in OLEDs Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-07 Yachen Xu, Jialu Gu, Lulu Zhou, Bingjia Zhao, Yangyang Zhu, Wei Shi, Bin Wei
Organic light-emitting diodes (OLEDs) have become one of the mainstream lighting and display technologies. The vacuum thermal evaporation is the most widely adopted method for the preparation of organic and metal materials of OLEDs. The thermal deposition of the commonly used silver (Ag) and aluminum (Al) electrodes requires high temperature and long time, which greatly increases the cost of the fabricating
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Over 43%-power-efficiency GaInN-based photoelectric transducer on free-standing GaN substrate for optical wireless power transmission system Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-07 Takahiro Fujisawa, Nan Hu, Tomoki Kojima, Takashi Egawa, Makoto Miyoshi
We investigated the GaInN-based photoelectric transducers (PTs) aiming at the application to optical wireless power transmission systems. A PT device structure with Ga0.9In0.1N multiple-quantum-wells (MQWs) as a light absorption layer was grown on a free-standing GaN substrate by metalorganic chemical vapor deposition and subjected to the device fabrication. The PT performance was evaluated via the
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Understanding the effects of annealing induced structural transformations on the UVC absorbance and other optical properties of RF sputter deposited Ga2O3 thin films Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-04 Keerthana C S, Anjana S Nair, Sreepriya K, Jiya James, Santhosh Kumar, N V Unnikrishnan, Saritha A C
Gallium oxide (Ga2O3) is a transparent material with high absorption in the UVC region of the electromagnetic spectrum and hence is a very important candidate in the field of short wavelength optical device fabrication. A proper understanding of the different optical parameters is necessary for developing more efficient coatings and devices. In this work, changes in the optical behavior of Ga2O3 thin
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Correlation between defect properties and the performance of eco-friendly CsSnI3-based perovskite solar cells Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-03-01 M Mottakin, Mohd Sukor Su’Ait, Puvaneswaran Chelvanathan, Md Ariful Islam, Md Shahiduzzaman, Mohd Adib Ibrahim, Ghulam Muhammad, Md Akhtaruzzaman
This study investigates the potential use of eco-friendly, all-inorganic cesium tin iodide (CsSnI3) perovskite (PVK) as an absorber layer. Despite having higher temperature stability of CsSnI3, the challenge is to get a uniform and defect-free film that hinders the performance. To accomplish this goal, we investigated several performance-related variables for perovskite solar cells (PSCs), including
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The impacts of SiO2 atomic-layer-deposited passivation layer thickness on GaN-based green micro-LEDs Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-28 Youcai Deng, Jinlan Chen, Saijun Li, He Huang, Zhong Liu, Zijun Yan, Shouqiang Lai, Lijie Zheng, Tianzhi Yang, Zhong Chen, Tingzhu Wu
In this study, we fabricated 76 × 127 µm2 green GaN-based micro-light-emitting-diodes (micro-LEDs) with atomic-layer-deposited (ALD) SiO2 passivation layers whose thicknesses were 0, 15, and 100 nm. The optoelectrical and communication performances of these devices were measured and analysed. The current-voltage results showed that ALD technology reduced the leakage current and enhanced the forward
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TMD material investigation for a low hysteresis vdW NCFET logic transistor Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-28 I Blessing Meshach Dason, N Kasthuri, D Nirmal
Boltzmann limit is inevitable in conventional MOSFETs, which prevent them to be used for low-power applications. Research in device physics can address this problem by selection of proper materials satisfying our requirements. Recently, 2D transition metal di-chalcogenide (TMD) materials are gaining interest because they help alleviate short-channel effects and DIBL problems. The TMD materials are
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The superiority of the photocatalytic and antibacterial performance of mechanochemically synthesized CdS nanoparticles over solvothermal-prepared ones Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-28 Gairat Burashev, Batukhan Tatykayev, Matej Baláž, Natalya Khan, Ardak Jumagazieva, Zhanar Iskakbayeva, Anar Seysembekova, Saparbek Tugelbay, Nurshat Turgynbay, Almagul Niyazbayeva, Aleksandr Ilin, Mukhambetkali Burkitbayev, Zhandos Shalabayev
In this work, we have developed a facile, dry, and environmentally friendly mechanochemical method for the synthesis of cadmium sulfide (m-CdS) nanoparticles in a planetary ball mill using non-toxic precursors. Thiourea was for the first time used as a precursor of sulfide ion in room temperature solid state ball milling synthesis. For comparison of the mechanochemical approach with others, cadmium
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Low-voltage operating, high mobility top-gate structural flexible organic thin-film transistor with a one-step spin-coated binary polymer gate dielectric Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-23 Jing Su, Zhenxiang Yan, Yijie Lin, Wenfa Xie, Wei Wang
Low-voltage operation is one of the prerequisites for the practical applications of the organic thin-film transistors (OTFTs). Up to date, the most reported low-voltage operatable OTFTs use a bottom-gate structure, and are fabricated by several different technologies in the whole process, in which the organic semiconductors and/or gate dielectrics are prepared in the expensive vacuum equipment. The
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Theoretical prediction of a novel hexagonal narrow-gap silicon allotrope under high pressures Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-23 Huimin Hu, Jin-Ho Choi
Silicon material plays a vital role in contemporary technology-related fields, including electronics and the photovoltaics. There is a growing demand for exploring new silicon structures with potential applications, and numerous metastable structures have been reported. In this study, we present the prediction of a novel stable sp 3 hybridized silicon allotrope using particle swarm optimization global
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Potential design strategy of wide-bandgap semiconductor p-type β-Ga2O3 Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-23 Xinglin Liu, Jun Huang, Qiangmin Wei, Lei Ye
Wide bandgap semiconductor gallium oxide (β-Ga2O3) has emerged as a prominent material in the field of high-power microelectronics and optoelectronics, due to its excellent and stable performance. However, the lack of high-quality p-type β-Ga2O3 hinders the realization of its full potential. Here, we initially summarize the origins of p-type doping limitation in β-Ga2O3, followed by proposing four
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Optical, conductive, and ferroelectric properties of the first layer of dip-coated BiFeO3 films from methoxyethanol and acetic acid-based chemical dissolvents Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-23 Carolina J Diliegros-Godines, Francisco Javier Flores-Ruiz
The overall performance of the multilayer resulting in a sol-gel bismuth ferrite (BiFeO3) film will be primarily determined by the properties of the first layer, but this has yet to receive much attention, even though chemical and morphological defects of this layer can accumulate as the number of layers increases. Here, we perform an optical, conductive, and ferroelectric study of first layer (L 1)
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Design and simulation of a nano biosensor based on amorphous indium gallium zinc oxide (a-IGZO) thin film transistor Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-21 Zahra Ahangari
In this study, a biosensor utilizing a dielectric-modulated amorphous indium gallium zinc oxide (a-IGZO) thin film transistor (TFT) is introduced. TFT biosensors have garnered significant attention due to their heightened sensitivity, scalable nature, low power consumption, rapid electrical detection capabilities, and cost-effective means of mass production. By embedding a nano-cavity within the gate
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Improved light extraction efficiency of AlGaN DUV light emitting diodes using Al/MgF2-based highly reflective film Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-20 Peishan Li, Xiaoyue Huang, Yuqing Yang, Zhenghao Xia, Qiao Wang, Hang Chen, Xingfu Wang
AlGaN DUV light emitting diodes (DUV-LEDs) (275 nm emission) are safe, eco-friendly and smart alternatives for inactivating viruses and bacteria. However, DUV-LEDs suffer from the main bottleneck of low external quantum efficiencies, which are strongly associated with the low light extraction efficiency caused by the strong optical polarisation of Al-rich AlGaN. Optical simulation results show that
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Quantification of losses in bent waveguides within DBR-RW laser diodes emitting at 785 nm Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-16 Lara Sophie Theurer, Jan-Philipp Koester, André Müller, Martin Maiwald, Andrea Knigge, Bernd Sumpf, Günther Tränkle
An experimental study of straight and bent distributed Bragg reflector (DBR) ridge waveguide (RW) lasers and Fabry–Pérot (FP) RW lasers emitting at 785 nm is presented. To determine the losses introduced by the bent waveguides within DBR-RW lasers, different laser designs were manufactured and characterized. The bent waveguides investigated here within DBR-RW laser diodes are sine-shaped S-bends. S-bends
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Deep-ultraviolet LEDs with an Al-graded p-AlGaN layer exhibiting high wall-plug efficiency and high modulation bandwidth simultaneously Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-16 Bingyue Cui, Jie Yang, Xingfa Gao, Jiaheng He, Zhe Liu, Zhe Cheng, Yun Zhang
This work demonstrated a deep-ultraviolet (DUV) LED with an Al-graded p-AlGaN contact layer above the electron blocking layer to alleviate p-type contact resistance, the asymmetry of carriers transport, and the polarization effect. The fitting results from the ABC + f(n) model revealed that the LED has a higher radiative recombination coefficient than the conventional structures ever reported, which
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The Franz–Keldysh effect in the optical absorption spectrum of a TlGaSe2 layered semiconductor caused by charged native defects Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-15 Serdar Gören, Yasin Şale, MirHasan Yu Seyidov
The Franz–Keldysh effect in the optical absorption edge of a bulk TlGaSe2 layered semiconductor poled under an external electric field was investigated in the present work. The Franz–Keldysh shift below the optical bandgap absorption region, as well as the quasi-periodic oscillations above the fundamental bandgap of TlGaSe2, were observed. The measured changes in optical light absorption of the TlGaSe2
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Improving the structural performance of low-temperature sputtered AlN on silicon substrate Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-13 Yuchi Luo, Ye Yuan, Zhiwen Liang, Tianren Cai, Hengyi Yin, Yichen Zhao, Hongmeng Zhang, Jiakang Cao, Wenting Wan, Yanda Ji, Anli Yang, Qi Wang, Mingming Hao
Preparing high-quality AlN films at low temperatures is always highly demanded in plenty of application-fields, despite the high temperature is always necessary to enable the AlN crystallization. Therefore, improving the structural properties at low temperature is still challenging in the field. In the present work, a metal organic chemical vapor deposition (MOCVD) grown AlN nucleation layer is employed
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A novel split-gate trench MOSFET embedded with a high-k pillar for higher breakdown voltage Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-08 Li Huang, Xiaojin Li, Yabin Sun, Yanling Shi
A novel split-gate trench MOSFET embedded with a high-k pillar (HKP SGT-MOS) is proposed in this study. Numerous electric displacement lines are allowed to enter the high-k pillar introduced beneath the split gate, thus relieving the crowding of the electric field at the bottom corner of the split gate. Therefore, the HKP SGT-MOS can achieve a higher breakdown voltage (BV) without sacrificing its forward
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Polarization-doped n-p-i-p-n GaN-based parallel phototransistor with thick GaN absorption layer for achieving high responsivity Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-08 Zhengji Zhu, Chunshuang Chu, Kangkai Tian, Zhan Xuan, Zhiwei Xie, Ke Jiang, Yonghui Zhang, Xiaojuan Sun, Zi-Hui Zhang, Dabing Li
In this report, we propose a polarization-doped n-p-i-p-n GaN-based parallel phototransistor with thick GaN absorption layer. We employ an Al-composition-graded AlxGa1–xN layer for achieving p-type doping feature. We have studied the light propagation in the unintentionally doped GaN (i-GaN) absorption layer with different thicknesses, and the optimized thickness is 2 μm. As a result, the photo current
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Surface passivation properties of atomic-layer deposited hafnium oxide on a (100) β-Ga2O3 MOSFET Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-07 Seung Yoon Oh, Gyuhyung Lee, Jiyeon Ma, Geonwook Yoo
We report the effect of HfO2 passivation on the electrical characteristics of (100) β-Ga2O3 metal-oxide-semiconductor field-effect transistors (MOSFETs). The atomic-layer-deposited HfO2 layer with negative defect charges enhances the transconductance and subthreshold slope. A significant positive threshold voltage (V TH) shift of ∼32 V is induced after the passivation. Moreover, significantly less
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Review on magnetic/nonmagnetic heterojunction interface effects on spintronic MTJ devices Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-07 Yuhai Yuan, Yanfeng Jiang
Magnetic tunnel junctions (MTJs), as the core storage unit of magneto resistive random-access memory, plays important role in the cutting-edge spintronics. In the MTJ devices, there are multiple internal magnetic/nonmagnetic heterojunction structures. The heterojunction always consists of magnetic metals and magnetic insulators or nonmagnetic metals. The interface of the heterojunction has certain
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Integrated 2T1C pixel circuit with a-Si TFT and NMOS for active matrix mini-LED displays Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-07 Chenming Zhong, Guangyao Li, Xi Zheng, Lihong Zhu, Jianbang Zhuang, Yijun Lu, Zhong Chen, Weijie Guo
The 2T1C pixel driver circuit for mini-LED direct display has been proposed, which separates the switching transistor and the driver transistor from the same display substrate, replaces the driver transistor with n-metal oxide semiconductor (NMOS), and combines printed circuit board substrate and thin-film transistor (TFT) substrate to improve the driving capability of the circuit. The NMOS was soldered
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Anisotropic structural and optical properties of semi-polar (20–21) InGaN/GaN multiple quantum wells grown on patterned sapphire substrates Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-06 Yun Zhang, Maogao Gong, Kun Xing, Feifan Xu, Tao Tao, Zili Xie, Bin Liu, Rong Zhang
Semi-polar orientation owns the advantage of reduced internal piezoelectric fields by tilting the growth direction away from the conventional c-direction. The crystal symmetry and the balanced biaxial stress in growth plane are inevitably broken in the semi-polar orientation, leading to the appearance of anisotropic properties in both structural and optical performance. This report has investigated
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External electric field and UV-ozone treated Ti3C2T x -MXene nanosheets and their hole injection tailoring in UV organic light-emitting diodes Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-02-06 Wei Bai, Danni Wu, Yijin Tang, Zichuan Yi, Feng Chi, Liming Liu, Xiaowen Zhang
Solution-processed 2D nanosheets of Ti3C2T x -MXene have been facilely synthesized with ultrasonic-assisted liquid phase exfoliation. X-ray diffraction, scanning electron microscope, transmission electron microscope, atomic force microscopy and x-ray photoelectron spectroscopy measurements confirm that the Ti3C2T x -MXene nanosheets have been successfully synthesized, showing good film morphology and
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Fully-vertical GaN-on-SiC Schottky barrier diode with ultrathin AlGaN buffer layer Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-24 Yuting Sun, Yuxia Feng, Jia Wei, Maojun Wang, Xuelin Yang, Wenkang Mei, Yufei Yang, Bo Shen
In this letter, vertically conductive GaN epilayer on SiC substrate was achieved without the typically used conductive buffer layer. Here, in order to reduce the impacts of band offset of different layers on vertical conductivity and improve the vertical carrier transportation, an ultrathin AlGaN buffer layer was employed to replace the thick conductive buffer layer. Fully-vertical Schottky barrier
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Bi-directional threshold voltage shift of amorphous InGaZnO thin film transistors under alternating bias stress Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-23 Hyunjin Kim, Beom Jung Kim, Jungyeop Oh, Sung-Yool Choi, Hamin Park
Amorphous InGaZnO (a-IGZO) has attracted a lot of attention as a high-mobility channel material for thin film transistors (TFTs). However, the instability mechanism involving threshold voltage and subthreshold swing (SS) in a-IGZO TFTs still requires further investigation. In this study, we investigated the electrical instability of amorphous InGaZnO TFTs subjected to alternating positive and negative
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Strain engineering and strain measurement by spring tethers on suspended epitaxial GaN-on-Si photonic crystal devices Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-23 Jun Wang, Romuald Houdré
Suspended epitaxial gallium nitride (GaN) on silicon (Si) photonic crystal devices suffer from large residual tensile strain, especially for long waveguides, because fine structures tend to crack due to large stress. By introducing spring-like tethers, designed by the combination of a spring network model and finite element method simulations, the stress at critical locations was mitigated and the
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Impact of CdSeTe and CdSe film deposition parameter on the properties of CdSeTe/CdTe absorber structure for solar cell applications Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-23 Ali Çiriş, Yavuz Atasoy, Murat Tomakin, Abdullah Karaca, Tayfur Küçükömeroğlu, Emin Bacaksız
In this study, the effect of depositing CdSeTe and CdTe layers at different substrate temperatures (STs) by evaporation in vacuum on the properties of the CdSeTe/CdTe stacks was investigated. First, CdSeTe layers in stack structure were grown at STs of 150 °C, 200 °C and 250 °C and then CdTe layers on the CdSeTe produced with the optimum temperature were coated at STs of 150 °C, 200 °C and 250 °C.
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Terahertz dielectric properties of Fe3O4 thin films deposited on Si (100) substrate Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-19 Ashish Khandelwal, L S Sharath Chandra, Shilpam Sharma, Archna Sagdeo, R J Choudhary, M K Chattopadhyay
Fe3O4 is considered to be a promising material for terahertz spintronic applications as well as for stealth technology. However, the optical properties of Fe3O4 in the thin film form at terahertz frequencies are not reported in literature. In this article, we present the frequency and temperature dependence of dielectric permittivity (ε 1) and optical conductivity (σ 1) of Fe3O4 films deposited on
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Design and simulation of high performance β-Ga2O3 super barrier rectifier with a current blocking layer Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-18 Zhenghua Wang, Lei Yuan, Bo Peng, Xinming Xie, Yuming Zhang, Renxu Jia
In this work, a β-Ga2O3 super barrier rectifier with a current blocking layer (CSBR) is proposed. Its static characteristics, dynamic characteristics and surge capability are investigated by TCAD simulation. The Baliga’s figure of merit (BFOM) can reach 1.62 GW cm−2 with the on-resistance of 3.68 mΩ cm−2 and the breakdown voltage of 2447 V, exhibiting excellent performance. Foremost, the turn-on and
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A novel low trigger voltage low leakage SCR for low-voltage ESD protection Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-12 Jizhi Liu, Feilong Yang, Yilin Liu
Reducing trigger voltage has always been a research hotspot in low-voltage electrostatic discharge (ESD) protection applications for integrated circuit. Thus, a novel low trigger voltage low leakage silicon-controlled rectifier (LTVLLSCR) for low-voltage ESD protection has been proposed. The proposed device uses a PMOS connected with the SCR to reduce the trigger voltage and the PMOS gate can be applied
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Multiple factors of regulation for transient negative capacitance in PbZr(1−x)Ti(x)O3 ferroelectric thin films Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-12 Hai-Ze Cao, Yong-Guang Xiao, Ning-Jie Ma, Li-Sha Yang, Yong Jiang, Ke Xiong, Gang Li, Jun Ouyang, Ming-Hua Tang
The negative capacitance (NC) of ferroelectric (FE) materials can effectively break the ‘Boltzmann tyranny’ and drive the continuation scaling of Moore’s law. In this work, to find a novel way for amplifying the transient NC, a series network of external resistors and PbZr(1−x)Ti(x)O3 (PZT) FE capacitors was constructed. Uniform modeling and simulation were performed using Kirchhoff’s current law,
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Low-resistive gate module for RF GaN-HFETs by electroplating Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-12 H Yazdani, A Thies, P Stützle, O Bengtsson, O Hilt, W Heinrich, J Würfl
This paper presents a novel approach for reducing the gate resistance (R g) of K and Ka-band GaN HFETs with 150 nm gate length through a new gate metallization technique. The method involves increasing the gate cross-section via galvanic metallization using FBH’s Ir-sputter gate technology, which allows an increase in gate metal thickness from the current 0.4 μm to approximately 1.0 μm for the transistors
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Oxygen reduction through specific surface area control of AlN powder for AlN single-crystal growth by physical vapor transport Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-12 Ze-Ren Wang, Xing-Yu Zhu, Qi-Yue Zhao, Jie-Jun Wu, Tong-Jun Yu
In the physical vapor transport (PVT) growth of AlN, re-oxidation of aluminum nitride (AlN) source powder happening in the process of setting seed crystal into crucible seems to be unavoidable. This process introduces oxygen just before AlN growth and has a significant impact on the crystal quality. In this paper, a high and low-temperature alternative sintering method (HLAS) is proposed based on the
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Dual-directional SCR device with dual-gate controlled mechanism for ESD protection in photoelectric chip Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-12 Yujie Liu, Yang Wang, Jian Yang, Xiangliang Jin
The dual-directional silicon-controlled rectifier (DDSCR) is an electrostatic discharge (ESD) protection device. It can provide positive and negative ESD surge paths and has excellent robustness. However, industry-level sensors operating in strong electromagnetic interference environments impose higher reliability requirements on photoelectric chips. This paper proposed a novel DDSCR with a dual-gate
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An ultra-high-frequency memristor circuit model Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-04 Yanji Wang, Yu Wang, Yi Liu, Yanzhong Zhang, Yu Yan, Youde Hu, Xinpeng Wang, Hao Zhang, Rongqing Xu, Yi Tong
In the context of sixth-generation (6G) wireless communications technology, advanced radio-frequency switches are required to accommodate high-frequency terahertz range and complex modulation techniques. This paper proposes a flexible charge-controlled memristor model specifically designed for ultra-high-frequency applications. It describes in detail the derivation of the behavior model of the proposed
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Phase transformation on HZO ferroelectric layer in ferroelectric random-access memory induced by x-ray irradiation Semicond. Sci. Technol. (IF 1.9) Pub Date : 2024-01-04 Chung-Wei Wu, Po-Hsun Chen, Ting-Chang Chang, Yung-Fang Tan, Shih-Kai Lin, Yu-Hsuan Yeh, Yong-Ci Zhang, Hsin-Ni Lin, Kai-Chun Chang, Chien-Hung Yeh, Simon Sze
In this study, electrical measurements on ferroelectric random-access memory by prior x-ray irradiation are conducted. Compared with an unirradiated device, parameters such as current leakage and remnant polarization of the irradiated device were unexpectedly improved. Besides, better reliabilities including the number of endurance times and retention time have also been demonstrated. To clarify the
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Silicon ultrafast recovery diode with leakage current reduced via the combined lifetime process of gold diffusion and electron-beam irradiation Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-29 Hideto Onishi, Hajime Shirai
We investigated the reduction in the reverse-biased leakage current of Si ultrafast recovery diodes via a combined lifetime process involving Au diffusion and bulk electron-beam irradiation (EI). The leakage current of the combined-processed diode was significantly reduced to less than one-third of that of the diode processed solely with Au diffusion, maintaining a similar switching time of 32 ns.
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Fabrication of a freestanding AlN substrate via HVPE homoepitaxy on a PVT-AlN substrate Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-27 Ting Liu, Qian Zhang, Xu Li, Minghao Chen, Chunhua Du, Maosong Sun, Jia Wang, Shuxin Tan, Jicai Zhang
Hydride vapor phase epitaxy (HVPE) is employed for the homoepitaxial development of AlN thick films on AlN substrates grown via physical vapor transport (PVT). A freestanding AlN substrate with a 200 μm thickness is then obtained by mechanically grinding away the PVT-AlN substrate. The as-grown HVPE AlN layer has a smooth surface with long parallel atomic steps. The freestanding HVPE-AlN substrate
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Reliability of enhancement-mode p-GaN gate GaN HEMT with multiple field plates Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-27 Yingqiang Wei, Jinghe Wei, Wei Zhao, Suzhen Wu, Yidan Wei, Meijie Liu, Zhiyuan Sui, Ying Zhou, Yuqi Li, Hong Chang, Fei Ji, Weibin Wang, Lijun Yang, Guozhu Liu
In this paper, we fabricate enhancement-mode p-GaN gate GaN HEMTs with multiple field plates (MFPs) and analyze the reliability of the devices by means of simulation and experiment. Simulations of the electric-field distribution indicate that the MFPs effectively weaken the electric field peak near the gate to below the theoretical breakdown value and smooth the electric field between the gate edge
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A review of three-dimensional structure-controlled InGaN quantum wells for efficient visible polychromatic light emitters Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-21 Mitsuru Funato, Yoshinobu Matsuda, Yoichi Kawakami
This paper reviews the development of three-dimensional (3D) structure-controlled InGaN quantum wells (QWs) for highly efficient multiwavelength emitters without using phosphors. Specifically, two representative structures are reviewed: 3D structures composed of stable planes with low surface energies and 3D structures composed of unstable planes. In the early stage of the research, 3D structures were
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Epitaxial growth of high-quality Ge layers on Si with Ge2H6 under UHV-CVD conditions Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-20 Changjiang Xie, Yue Li, Chi Xu, Yixin Wang, Hui Cong, Chunlai Xue
Epitaxial growth of Ge films on Si(100) substrates has been studied under ultra-high vacuum chemical vapor deposition (CVD) conditions by using digermane (Ge2H6) as the precursor. It was found out that high quality layers with thicknesses beyond 500 nm could be produced at complementary metal–oxide–semiconductor compatible conditions, demonstrating low defect density, sharp and narrow x-ray diffraction
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A novel 650 V snapback-free PMOS-RC-SJBT with low switching and reverse recovery losses Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-19 Yuanzhen Yang, Luping Li, Zehong Li, Qianshen Rao, Peng Chen, Min Ren
A novel 650 V Snapback-free Reverse-conducting Super-junction (SJ) insulated gate bipolar transistor (RC-SJBT) with low switching and reverse recovery loss is proposed and investigated in paper. In where, SJ pillar acts as the drift region, meanwhile PMOS and Schottky are combined on the cathode side. Under the action of SJ pillar, the snapback is effectively suppressed and Von − Eoff trade-off of
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Comparative analysis of junctionless and inversion-mode nanosheet FETs for self-heating effect mitigation Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-12 Do Gyun An, Garam Kim, Hyunwoo Kim, Sangwan Kim, Jang Hyun Kim
Artificial intelligence computing requires hardware like central processing units and graphic processing units for data processing. However, excessive heat generated during computations remains a challenge. The paper focuses on the heat issue in logic devices caused by transistor structures. To address the problem, the operational mechanism of the Junctionless Field-Effect Transistor (JLFET) is investigated
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Recent progress in modifications of g-C3N4 for photocatalytic hydrogen evolution and CO2 reduction Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-11 Garima Rana, Pooja Dhiman, Amit Kumar, Elmuez A Dawi, Gaurav Sharma
Photocatalytic H2 evolution and CO2 reduction are promising technologies for addressing environmental and energy issues. g-C3N4 is one of most promising materials to form improved catalysts because of its exceptional electrical structure, physical and chemical characteristics, and distinctive metal-free feature. This article provides a summary of current advancements in g-C3N4-based catalysts from
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Efficiency improvement of Cu(In(1−x)Ga x )Se2 solar cell using copper barium tin sulfide as back surface field layer and bandgap grading technique Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-07 Alok Kumar Patel, Rajan Mishra, Sanjay Kumar Soni
This work proposes the simulation of graded CuIn1−xGaxSe2 –based solar cell with copper barium tin sulfide (CBTS) compounds as a back surface field (BSF) layer using the SCAPS-1D software. The CBTS BSF layer reduces the charge carrier losses on the back contact side and creates an extra BSF that helps in extracting holes toward the back contact. To utilize the maximum spectrum absorption range, three
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Improving vertical GaN p–n diode performance with room temperature defect mitigation Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-07 Nahid Sultan Al-Mamun, James Gallagher, Alan G Jacobs, Karl D Hobart, Travis J Anderson, Brendan P Gunning, Robert J Kaplar, Douglas E Wolfe, Aman Haque
Defect mitigation of electronic devices is conventionally achieved using thermal annealing. To mobilize the defects, very high temperatures are necessary. Since thermal diffusion is random in nature, the process may take a prolonged period of time. In contrast, we demonstrate a room temperature annealing technique that takes only a few seconds. The fundamental mechanism is defect mobilization by atomic
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Insights to the production of SnS-cubic thin films by vacuum thermal evaporation for photovoltaics Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-06 Fabiola De Bray Sánchez, M T S Nair, P K Nair
Thin films of SnS-CUB with a lattice constant of 11.6 Å, 32 units of SnS per cell and an optical bandgap (E g) of 1.7 eV (direct), are mostly produced by chemical techniques. This cubic polymorph is distinct from its orthorhombic polymorph (SnS-ORT) with an E g of 1.1 eV. This work is on the deposition of SnS-CUB thin films of 100–300 nm in thickness by thermal evaporation at substrate temperatures
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Anti-reflective MX (M = Sc and Y; X = N, P, As, Sb and Bi) monolayers: structural, electronic and optical study Semicond. Sci. Technol. (IF 1.9) Pub Date : 2023-12-04 Shoeib Babaee Touski, Manouchehr Hosseini, Alireza Kokabi
In this paper, the structural, electronic and optical properties of tetragonal binary monolayers of MX (M = Sc, Y; X = As, Bi, N, P, Sb) are investigated using the density functional theory. The optical study demonstrates that ScN and YN compounds are promising anti-reflective materials. All compounds are found to be semiconductors with a bandgap in the range of 0.45–1.8 eV. Among these compounds,