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975 nm multimode semiconductor lasers with high-order Bragg diffraction gratings J. Semicond. Pub Date : 2024-03-01 Zhenwu Liu, Li Zhong, Suping Liu, Xiaoyu Ma
The 975 nm multimode diode lasers with high-order surface Bragg diffraction gratings have been simulated and calculated using the 2D finite difference time domain (FDTD) algorithm and the scattering matrix method (SMM). The periods and etch depth of the grating parameters have been optimized. A board area laser diode (BA-LD) with high-order diffraction gratings has been designed and fabricated. At
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Reliable ferroelectricity down to cryogenic temperature in wake-up free Hf0.5Zr0.5O2 thin films by thermal atomic layer deposition J. Semicond. Pub Date : 2024-03-01 Shuyu Wu, Rongrong Cao, Hao Jiang, Yu Li, Xumeng Zhang, Yang Yang, Yan Wang, Yingfen Wei, Qi Liu
The performance and reliability of ferroelectric thin films at temperatures around a few Kelvin are critical for their application in cryo-electronics. In this work, TiN/Hf0.5Zr0.5O2/TiN capacitors that are free from the wake-up effect are investigated systematically from room temperature (300 K) to cryogenic temperature (30 K). We observe a consistent decrease in permittivity (ε r) and a progressive
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Physical insights into trapping effects on vertical GaN-on-Si trench MOSFETs from TCAD J. Semicond. Pub Date : 2024-03-01 Nicolò Zagni, Manuel Fregolent, Andrea Del Fiol, Davide Favero, Francesco Bergamin, Giovanni Verzellesi, Carlo De Santi, Gaudenzio Meneghesso, Enrico Zanoni, Christian Huber, Matteo Meneghini, Paolo Pavan
Vertical GaN power MOSFET is a novel technology that offers great potential for power switching applications. Being still in an early development phase, vertical GaN devices are yet to be fully optimized and require careful studies to foster their development. In this work, we report on the physical insights into device performance improvements obtained during the development of vertical GaN-on-Si
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Visible-to-near-infrared photodetectors based on SnS/SnSe2 and SnSe/SnSe2 p−n heterostructures with a fast response speed and high normalized detectivity J. Semicond. Pub Date : 2024-03-01 Xinfa Zhu, Weishuai Duan, Xiancheng Meng, Xiyu Jia, Yonghui Zhang, Pengyu Zhou, Mengjun Wang, Hongxing Zheng, Chao Fan
The emergent two-dimensional (2D) material, tin diselenide (SnSe2), has garnered significant consideration for its potential in image capturing systems, optical communication, and optoelectronic memory. Nevertheless, SnSe2-based photodetection faces obstacles, including slow response speed and low normalized detectivity. In this work, photodetectors based on SnS/SnSe2 and SnSe/SnSe2 p−n heterostructures
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GHz photon-number resolving detection with high detection efficiency and low noise by ultra-narrowband interference circuits J. Semicond. Pub Date : 2024-03-01 Tingting Shi, Yuanbin Fan, Zhengyu Yan, Lai Zhou, Yang Ji, Zhiliang Yuan
We demonstrate the photon-number resolution (PNR) capability of a 1.25 GHz gated InGaAs single-photon avalanche photodiode (APD) that is equipped with a simple, low-distortion ultra-narrowband interference circuit for the rejection of its background capacitive response. Through discriminating the avalanche current amplitude, we are able to resolve up to four detected photons in a single detection gate
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Behavior of exciton in direct−indirect band gap Al x Ga1−x As crystal lattice quantum wells J. Semicond. Pub Date : 2024-03-01 Yong Sun, Wei Zhang, Shuang Han, Ran An, Xin-Sheng Tang, Xin-Lei Yu, Xiu-Juan Miao, Xin-Jun Ma, Xianglian, Pei-Fang Li, Cui-Lan Zhao, Zhao-Hua Ding, Jing-Lin Xiao
Excitons have significant impacts on the properties of semiconductors. They exhibit significantly different properties when a direct semiconductor turns in to an indirect one by doping. Huybrecht variational method is also found to influence the study of exciton ground state energy and ground state binding energy in Al x Ga1−x As semiconductor spherical quantum dots. The Al x Ga1−x As is considered
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Emission and capture characteristics of deep hole trap in n-GaN by optical deep level transient spectroscopy J. Semicond. Pub Date : 2024-03-01 Jin Sui, Jiaxiang Chen, Haolan Qu, Yu Zhang, Xing Lu, Xinbo Zou
Emission and capture characteristics of a deep hole trap (H1) in n-GaN Schottky barrier diodes (SBDs) have been investigated by optical deep level transient spectroscopy (ODLTS). Activation energy (E emi) and capture cross-section (σ p) of H1 are determined to be 0.75 eV and 4.67 × 10−15 cm2, respectively. Distribution of apparent trap concentration in space charge region is demonstrated. Temperature-enhanced
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A novel one-time-programmable memory unit based on Schottky-type p-GaN diode J. Semicond. Pub Date : 2024-03-01 Chao Feng, Xinyue Dai, Qimeng Jiang, Sen Huang, Jie Fan, Xinhua Wang, Xinyu Liu
In this work, a novel one-time-programmable memory unit based on a Schottky-type p-GaN diode is proposed. During the programming process, the junction switches from a high-resistance state to a low-resistance state through Schottky junction breakdown, and the state is permanently preserved. The memory unit features a current ratio of more than 103, a read voltage window of 6 V, a programming time of
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Development of in situ characterization techniques in molecular beam epitaxy J. Semicond. Pub Date : 2024-03-01 Chao Shen, Wenkang Zhan, Manyang Li, Zhenyu Sun, Jian Tang, Zhaofeng Wu, Chi Xu, Bo Xu, Chao Zhao, Zhanguo Wang
Ex situ characterization techniques in molecular beam epitaxy (MBE) have inherent limitations, such as being prone to sample contamination and unstable surfaces during sample transfer from the MBE chamber. In recent years, the need for improved accuracy and reliability in measurement has driven the increasing adoption of in situ characterization techniques. These techniques, such as reflection high-energy
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An advanced theoretical approach to study super-multiperiod superlattices: theory vs experiments J. Semicond. Pub Date : 2024-02-01 Alexander Sergeevich Dashkov, Semyon Andreevich Khakhulin, Dmitrii Alekseevich Shapran, Gennadii Fedorovich Glinskii, Nikita Andreevich Kostromin, Alexander Leonidovich Vasiliev, Sergey Nikolayevich Yakunin, Oleg Sergeevich Komkov, Evgeniy Viktorovich Pirogov, Maxim Sergeevich Sobolev, Leonid Ivanovich Goray, Alexei Dmitrievich Bouravleuv
A new theoretical method to study super-multiperiod superlattices has been developed. The method combines the precision of the 8-band kp-method with the flexibility of the shooting method and the Monte Carlo approach. This method was applied to examine the finest quality samples of super-multiperiod Al0.3Ga0.7As/GaAs superlattices grown by molecular beam epitaxy. The express photoreflectance spectroscopy
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Controllable thermal rectification design for buildings based on phase change composites J. Semicond. Pub Date : 2024-02-01 Hengbin Ding, Xiaoshi Li, Tianhang Li, Xiaoyong Zhao, He Tian
Phase-change material (PCM) is widely used in thermal management due to their unique thermal behavior. However, related research in thermal rectifier is mainly focused on exploring the principles at the fundamental device level, which results in a gap to real applications. Here, we propose a controllable thermal rectification design towards building applications through the direct adhesion of composite
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Controllable step-flow growth of GaN on patterned freestanding substrate J. Semicond. Pub Date : 2024-02-01 Peng Wu, Jianping Liu, Lei Hu, Xiaoyu Ren, Aiqin Tian, Wei Zhou, Fan Zhang, Xuan Li, Masao Ikeda, Hui Yang
A new kind of step-flow growth mode is proposed, which adopts sidewall as step source on patterned GaN substrate. The terrace width of steps originated from the sidewall was found to change with the growth temperature and ammonia flux. The growth mechanism is explained and simulated based on step motion model. This work helps better understand the behaviors of step advancement and puts forward a method
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Efficient flexible dye-sensitized solar cells from rear illumination based on different morphologies of titanium dioxide photoanode J. Semicond. Pub Date : 2024-02-01 Zhe He, Gentian Yue, Yueyue Gao, Chen Dong, Furui Tan
The TiO2 with nanoparticles (NPs), nanowires (NWs), nanorods (NRs) and nanotubes (NTs) structures were prepared by using a in-situ hydrothermal technique, and then proposed as a photoanode for flexible dye-sensitized solar cell (FDSSC). The influences of the morphology of TiO2 on the photovoltaic performances of FDSSCs were investigated. Under rear illumination of 100 mW·cm−2, the power conversion
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Progress in efficient doping of Al-rich AlGaN J. Semicond. Pub Date : 2024-02-01 Jiaming Wang, Fujun Xu, Lisheng Zhang, Jing Lang, Xuzhou Fang, Ziyao Zhang, Xueqi Guo, Chen Ji, Chengzhi Ji, Fuyun Tan, Xuelin Yang, Xiangning Kang, Zhixin Qin, Ning Tang, Xinqiang Wang, Weikun Ge, Bo Shen
The development of semiconductors is always accompanied by the progress in controllable doping techniques. Taking AlGaN-based ultraviolet (UV) emitters as an example, despite a peak wall-plug efficiency of 15.3% at the wavelength of 275 nm, there is still a huge gap in comparison with GaN-based visible light-emitting diodes (LEDs), mainly attributed to the inefficient doping of AlGaN with increase
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Two-step growth of β-Ga2O3 on c-plane sapphire using MOCVD for solar-blind photodetector J. Semicond. Pub Date : 2024-02-01 Peipei Ma, Jun Zheng, Xiangquan Liu, Zhi Liu, Yuhua Zuo, Buwen Cheng
In this work, a two-step metal organic chemical vapor deposition (MOCVD) method was applied for growing β-Ga2O3 film on c-plane sapphire. Optimized buffer layer growth temperature (T B) was found at 700 °C and the β-Ga2O3 film with full width at half maximum (FWHM) of 0.66° was achieved. A metal−semiconductor−metal (MSM) solar-blind photodetector (PD) was fabricated based on the β-Ga2O3 film. Ultrahigh
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Enhanced thermal emission from metal-free, fully epitaxial structures with epsilon-near-zero InAs layers J. Semicond. Pub Date : 2024-02-01 Karolis Stašys, Andrejus Geižutis, Jan Devenson
We introduce a novel method to create mid-infrared (MIR) thermal emitters using fully epitaxial, metal-free structures. Through the strategic use of epsilon-near-zero (ENZ) thin films in InAs layers, we achieve a narrow-band, wide-angle, and p-polarized thermal emission spectra. This approach, employing molecular beam epitaxy, circumvents the complexities associated with current layered structures
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Research progress of alkaline earth metal iron-based oxides as anodes for lithium-ion batteries J. Semicond. Pub Date : 2024-02-01 Mingyuan Ye, Xiaorui Hao, Jinfeng Zeng, Lin Li, Pengfei Wang, Chenglin Zhang, Li Liu, Fanian Shi, Yuhan Wu
Anode materials are an essential part of lithium-ion batteries (LIBs), which determine the performance and safety of LIBs. Currently, graphite, as the anode material of commercial LIBs, is limited by its low theoretical capacity of 372 mA·h·g−1, thus hindering further development toward high-capacity and large-scale applications. Alkaline earth metal iron-based oxides are considered a promising candidate
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Bidirectional rectifier with gate voltage control based on Bi2O2Se/WSe2 heterojunction J. Semicond. Pub Date : 2024-01-01 Ruonan Li, Fangchao Lu, Jiajun Deng, Xingqiu Fu, Wenjie Wang, He Tian
Two-dimensional (2D) WSe2 has received increasing attention due to its unique optical properties and bipolar behavior. Several WSe2-based heterojunctions exhibit bidirectional rectification characteristics, but most devices have a lower rectification ratio. In this work, the Bi2O2Se/WSe2 heterojunction prepared by us has a type Ⅱ band alignment, which can vastly suppress the channel current through
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240 nm AlGaN-based deep ultraviolet micro-LEDs: size effect versus edge effect J. Semicond. Pub Date : 2024-01-01 Shunpeng Lu, Jiangxiao Bai, Hongbo Li, Ke Jiang, Jianwei Ben, Shanli Zhang, Zi-Hui Zhang, Xiaojuan Sun, Dabing Li
240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated. Then, the external quantum efficiency (EQE) and light extraction efficiency (LEE) are systematically investigated by comparing size and edge effects. Here, it is revealed that the peak optical output power increases by 81.83% with the size shrinking from 50.0 to 25.0 μm. Thereinto, the LEE increases by 26.21% and the LEE
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Electrical properties and structural optimization of GaN/InGaN/GaN tunnel junctions grown by molecular beam epitaxy J. Semicond. Pub Date : 2024-01-01 Jun Fang, Fan Zhang, Wenxian Yang, Aiqin Tian, Jianping Liu, Shulong Lu, Hui Yang
The InGaN films and GaN/InGaN/GaN tunnel junctions (TJs) were grown on GaN templates with plasma-assisted molecular beam epitaxy. As the In content increases, the quality of InGaN films grown on GaN templates decreases and the surface roughness of the samples increases. V-pits and trench defects were not found in the AFM images. p++-GaN/InGaN/n++-GaN TJs were investigated for various In content, InGaN
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Anisotropic etching mechanisms of 4H-SiC: Experimental and first-principles insights J. Semicond. Pub Date : 2024-01-01 Guang Yang, Lingbo Xu, Can Cui, Xiaodong Pi, Deren Yang, Rong Wang
Molten-alkali etching has been widely used to reveal dislocations in 4H silicon carbide (4H-SiC), which has promoted the identification and statistics of dislocation density in 4H-SiC single crystals. However, the etching mechanism of 4H-SiC is limited misunderstood. In this letter, we reveal the anisotropic etching mechanism of the Si face and C face of 4H-SiC by combining molten-KOH etching, X-ray
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11.2 W/mm power density AlGaN/GaN high electron-mobility transistors on a GaN substrate J. Semicond. Pub Date : 2024-01-01 Yansheng Hu, Yuangang Wang, Wei Wang, Yuanjie Lv, Hongyu Guo, Zhirong Zhang, Hao Yu, Xubo Song, Xingye zhou, Tingting Han, Shaobo Dun, Hongyu Liu, Aimin Bu, Zhihong Feng
In this letter, high power density AlGaN/GaN high electron-mobility transistors (HEMTs) on a freestanding GaN substrate are reported. An asymmetric Γ-shaped 500-nm gate with a field plate of 650 nm is introduced to improve microwave power performance. The breakdown voltage (BV) is increased to more than 200 V for the fabricated device with gate-to-source and gate-to-drain distances of 1.08 and 2.92
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Optimized operation scheme of flash-memory-based neural network online training with ultra-high endurance J. Semicond. Pub Date : 2024-01-01 Yang Feng, Zhaohui Sun, Yueran Qi, Xuepeng Zhan, Junyu Zhang, Jing Liu, Masaharu Kobayashi, Jixuan Wu, Jiezhi Chen
With the rapid development of machine learning, the demand for high-efficient computing becomes more and more urgent. To break the bottleneck of the traditional Von Neumann architecture, computing-in-memory (CIM) has attracted increasing attention in recent years. In this work, to provide a feasible CIM solution for the large-scale neural networks (NN) requiring continuous weight updating in online
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A 24−30 GHz 8-element dual-polarized 5G FR2 phased-array transceiver IC with 20.8-dBm TX OP1dB and 4.1-dB RX NFin 65-nm CMOS J. Semicond. Pub Date : 2024-01-01 Yongran Yi, Dixian Zhao, Jiajun Zhang, Peng Gu, Chenyu Xu, Yuan Chai, Huiqi Liu, Xiaohu You
This article presents an 8-element dual-polarized phased-array transceiver (TRX) front-end IC for millimeter-wave (mm-Wave) 5G new radio (NR). Power enhancement technologies for power amplifiers (PA) in mm-Wave 5G phased-array TRX are discussed. A four-stage wideband high-power class-AB PA with distributed-active-transformer (DAT) power combining and multi-stage second-harmonic traps is proposed, ensuring
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GaN based ultraviolet laser diodes J. Semicond. Pub Date : 2024-01-01 Jing Yang, Degang Zhao, Zongshun Liu, Yujie Huang, Baibin Wang, Xiaowei Wang, Yuheng Zhang, Zhenzhuo Zhang, Feng Liang, Lihong Duan, Hai Wang, Yongsheng Shi
In the past few years, many groups have focused on the research and development of GaN-based ultraviolet laser diodes (UV LDs). Great progresses have been achieved even though many challenges exist. In this article, we analyze the challenges of developing GaN-based ultraviolet laser diodes, and the approaches to improve the performance of ultraviolet laser diode are reviewed. With these techniques
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Enhanced magnetic anisotropy and high hole mobility in magnetic semiconductor Ga1-x-y Fe x Ni y Sb J. Semicond. Pub Date : 2024-01-01 Zhi Deng, Hailong Wang, Qiqi Wei, Lei Liu, Hongli Sun, Dong Pan, Dahai Wei, Jianhua Zhao
(Ga,Fe)Sb is a promising magnetic semiconductor (MS) for spintronic applications because its Curie temperature (T C) is above 300 K when the Fe concentration is higher than 20%. However, the anisotropy constant K u of (Ga,Fe)Sb is below 7.6 × 103 erg/cm3 when Fe concentration is lower than 30%, which is one order of magnitude lower than that of (Ga,Mn)As. To address this issue, we grew Ga1-x-y Fe x
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High-temperature annealing of ( ) β-Ga2O3 substrates for reducing structural defects after diamond sawing J. Semicond. Pub Date : 2023-12-01 Pavel Butenko, Michael Boiko, Mikhail Sharkov, Aleksei Almaev, Aleksnder Kitsay, Vladimir Krymov, Anton Zarichny, Vladimir Nikolaev
A commercial epi-ready ( ) β-Ga2O3 wafer was investigated upon diamond sawing into pieces measuring 2.5 × 3 mm2. The defect structure and crystallinity in the cut samples has been studied by X-ray diffraction and a selective wet etching technique. The density of defects was estimated from the average value of etch pits calculated, including near-edge regions, and was obtained close to 109 cm−2. Blocks
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Multiple SiGe/Si layers epitaxy and SiGe selective etching for vertically stacked DRAM J. Semicond. Pub Date : 2023-12-01 Zhenzhen Kong, Hongxiao Lin, Hailing Wang, Yanpeng Song, Junjie Li, Xiaomeng Liu, Anyan Du, Yuanhao Miao, Yiwen Zhang, Yuhui Ren, Chen Li, Jiahan Yu, Jinbiao Liu, Jingxiong Liu, Qinzhu Zhang, Jianfeng Gao, Huihui Li, Xiangsheng Wang, Junfeng Li, Henry H. Radamson, Chao Zhao, Tianchun Ye, Guilei Wang
Fifteen periods of Si/Si0.7Ge0.3 multilayers (MLs) with various SiGe thicknesses are grown on a 200 mm Si substrate using reduced pressure chemical vapor deposition (RPCVD). Several methods were utilized to characterize and analyze the ML structures. The high resolution transmission electron microscopy (HRTEM) results show that the ML structure with 20 nm Si0.7Ge0.3 features the best crystal quality
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From kesterite 2D nanosheets to wurtzite 1D nanorods: controllable synthesis of Cu−Zn−Sn−S and their application in electrocatalytic hydrogen evolution J. Semicond. Pub Date : 2023-12-01 Yu Li, Shuaibing Wang, Jie Chen, Ouyang Lin, Zhe Yin, Chunhe Yang, Aiwei Tang
As typical quarternary copper-based chalcogenides, Cu–Zn–Sn–S nanocrystals (CZTS NCs) have emerged as a new-fashioned electrocatalyst in hydrogen evolution reactions (HERs). Oleylamine (OM), a reducing surfactant and solvent, plays a significant role in the assisting synthesis of CZTS NCs due to the ligand effect. Herein, we adopted a facile one-pot colloidal method for achieving the structure evolution
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Demonstration of a manufacturable SOT-MRAM multiplexer array towards industrial applications J. Semicond. Pub Date : 2023-12-01 Chuanpeng Jiang, Jinhao Li, Hongchao Zhang, Shiyang Lu, Pengbin Li, Chao Wang, Zhongkui Zhang, Zhengyi Hou, Xu Liu, Jiagao Feng, He Zhang, Hui Jin, Gefei Wang, Hongxi Liu, Kaihua Cao, Zhaohao Wang, Weisheng Zhao
We have successfully demonstrated a 1 Kb spin-orbit torque (SOT) magnetic random-access memory (MRAM) multiplexer (MUX) array with remarkable performance. The 1 Kb MUX array exhibits an in-die function yield of over 99.6%. Additionally, it provides a sufficient readout window, with a TMR/R P_sigma% value of 21.4. Moreover, the SOT magnetic tunnel junctions (MTJs) in the array show write error rates
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Hyperfine splitting and ferromagnetism in CdS : Mn nanoparticles for optoelectronic device applications J. Semicond. Pub Date : 2023-12-01 Madhavi Sharad Darekar, Praveen Beekanahalli Mokshanatha
Manganese (Mn) doped cadmium sulphide (CdS) nanoparticles were synthesized using a chemical method. It was possible to decrease CdS : Mn particle size by increasing Mn concentration. Investigation techniques such as ultraviolet−visible (UV−Vis) absorption spectroscopy and photoluminescence (PL) spectroscopy were used to determine optical properties of CdS : Mn nanoparticles. Size quantization effect
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Green synthesis of three-dimensional magnesium ferrite/titanium dioxide/reduced graphene from Garcinia mangostana extract for crystal violet photodegradation and antibacterial activity J. Semicond. Pub Date : 2023-12-01 Tong Hoang Lin, Che Quang Cong, Nguyen Thanh Hoai Nam, Hoang An, Nguyen Duy Hai, Ton That Buu, Thoi Le Nhat Binh, Hoang Le Minh, Lam Thanh Ngan, Hoang Thuy Kim Ngan, Du Chi Vi, Ta Dang Khoa, Nguyen Huu Hieu
In this study, three-dimensional porous magnesium ferrite/titanium dioxide/reduced graphene oxide (MgFe2O4-GM/TiO2/rGO (MGTG)) was successfully synthesized via green and hydrothermal-supported co-precipitation methods using the extract of Garcinia mangostana (G. mangostana) as a reducing agent. The characterization results indicate the successful formation of the nano/micro MgFe2O4 (MFO) and TiO2 on
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Controllable growth of wafer-scale PdS and PdS2 nanofilms via chemical vapor deposition combined with an electron beam evaporation technique J. Semicond. Pub Date : 2023-12-01 Hui Gao, Hongyi Zhou, Yulong Hao, Guoliang Zhou, Huan Zhou, Fenglin Gao, Jinbiao Xiao, Pinghua Tang, Guolin Hao
Palladium (Pd)-based sulfides have triggered extensive interest due to their unique properties and potential applications in the fields of electronics and optoelectronics. However, the synthesis of large-scale uniform PdS and PdS2 nanofilms (NFs) remains an enormous challenge. In this work, 2-inch wafer-scale PdS and PdS2 NFs with excellent stability can be controllably prepared via chemical vapor
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Switchable hidden spin polarization and negative Poisson's ratio in two-dimensional antiferroelectric wurtzite crystals J. Semicond. Pub Date : 2023-12-01 Zhuang Ma, Jingwen Jiang, Gui Wang, Peng Zhang, Yiling Sun, Zhengfang Qian, Jiaxin Zheng, Wen Xiong, Fei Wang, Xiuwen Zhang, Pu Huang
Two-dimensional (2D) antiferroelectric materials have raised great research interest over the last decade. Here, we reveal a type of 2D antiferroelectric (AFE) crystal where the AFE polarization direction can be switched by a certain degree in the 2D plane. Such 2D functional materials are realized by stacking the exfoliated wurtzite (wz) monolayers with “self-healable” nature, which host strongly
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Quantum cascade lasers grown by MOCVD J. Semicond. Pub Date : 2023-12-01 Yongqiang Sun, Guangzhou Cui, Kai Guo, Jinchuan Zhang, Ning Zhuo, Lijun Wang, Shuman Liu, Zhiwei Jia, Teng Fei, Kun Li, Junqi Liu, Fengqi Liu, Shenqiang Zhai
Sharing the advantages of high optical power, high efficiency and design flexibility in a compact size, quantum cascade lasers (QCLs) are excellent mid-to-far infrared laser sources for gas sensing, infrared spectroscopic, medical diagnosis, and defense applications. Metalorganic chemical vapor deposition (MOCVD) is an important technology for growing high quality semiconductor materials, and has achieved
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A review of automatic detection of epilepsy based on EEG signals J. Semicond. Pub Date : 2023-12-01 Qirui Ren, Xiaofan Sun, Xiangqu Fu, Shuaidi Zhang, Yiyang Yuan, Hao Wu, Xiaoran Li, Xinghua Wang, Feng Zhang
Epilepsy is a common neurological disorder that occurs at all ages. Epilepsy not only brings physical pain to patients, but also brings a huge burden to the lives of patients and their families. At present, epilepsy detection is still achieved through the observation of electroencephalography (EEG) by medical staff. However, this process takes a long time and consumes energy, which will create a huge
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A review on GaN HEMTs: nonlinear mechanisms and improvement methods J. Semicond. Pub Date : 2023-12-01 Chenglin Du, Ran Ye, Xiaolong Cai, Xiangyang Duan, Haijun Liu, Yu Zhang, Gang Qiu, Minhan Mi
The GaN HEMT is a potential candidate for RF applications due to the high frequency and large power handling capability. To ensure the quality of the communication signal, linearity is a key parameter during the system design. However, the GaN HEMT usually suffers from the nonlinearity problems induced by the nonlinear parasitic capacitance, transconductance, channel transconductance etc. Among them
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Incomplete charge transfer in CMOS image sensor caused by Si/SiO2 interface states in the TG channel J. Semicond. Pub Date : 2023-11-01 Xi Lu, Changju Liu, Pinyuan Zhao, Yu Zhang, Bei Li, Zhenzhen Zhang, Jiangtao Xu
CMOS image sensors produced by the existing CMOS manufacturing process usually have difficulty achieving complete charge transfer owing to the introduction of potential barriers or Si/SiO2 interface state traps in the charge transfer path, which reduces the charge transfer efficiency and image quality. Until now, scholars have only considered mechanisms that limit charge transfer from the perspectives
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Waveguide-integrated optical modulators with two-dimensional materials J. Semicond. Pub Date : 2023-11-01 Haitao Chen, Hongyuan Cao, Zejie Yu, Weike Zhao, Daoxin Dai
Waveguide-integrated optical modulators are indispensable for on-chip optical interconnects and optical computing. To cope with the ever-increasing amount of data being generated and consumed, ultrafast waveguide-integrated optical modulators with low energy consumption are highly demanded. In recent years, two-dimensional (2D) materials have attracted a lot of attention and have provided tremendous
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Development of a simple two-step lithography fabrication process for resonant tunneling diode using air-bridge technology J. Semicond. Pub Date : 2023-11-01 Swagata Samanta, Jue Wang, Edward Wasige
This article reports on the development of a simple two-step lithography process for double barrier quantum well (DBQW) InGaAs/AlAs resonant tunneling diode (RTD) on a semi-insulating indium phosphide (InP) substrate using an air-bridge technology. This approach minimizes processing steps, and therefore the processing time as well as the required resources. It is particularly suited for material qualification
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A review of the etched terminal structure of a 4H-SiC PiN diode J. Semicond. Pub Date : 2023-11-01 Hang Zhou, Jingrong Yan, Jialin Li, Huan Ge, Tao Zhu, Bingke Zhang, Shucheng Chang, Junmin Sun, Xue Bai, Xiaoguang Wei, Fei Yang
The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension (JTE) structures for power devices. However, achieving a gradual doping concentration change in the lateral direction is difficult for SiC devices since the diffusion constants of the implanted aluminum ions in SiC are much less than silicon. Many previously reported studies adopted
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Modulation bandwidth enhancement in monolithic integrated two-section DFB lasers based on the detuned loading effect J. Semicond. Pub Date : 2023-11-01 Yunshan Zhang, Yifan Xu, Shijian Guan, Jilin Zheng, Hongming Gu, Lianyan Li, Rulei Xiao, Tao Fang, Hui Zou, Xiangfei Chen
Modulation bandwidth enhancement in a directly modulated two-section distributed feedback (TS-DFB) laser based on a detuned loading effect is investigated and experimentally demonstrated. The results show that the 3-dB bandwidth of the TS-DFB laser is increased to 17.6 GHz and that chirp parameter can be reduced to 2.24. Compared to the absence of a detuned loading effect, there is a 4.6 GHz increase
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Performance optimization of tri-gate junctionless FinFET using channel stack engineering for digital and analog/RF design J. Semicond. Pub Date : 2023-11-01 Devenderpal Singh, Shalini Chaudhary, Basudha Dewan, Menka Yadav
This manuscript explores the behavior of a junctionless tri-gate FinFET at the nano-scale region using SiGe material for the channel. For the analysis, three different channel structures are used: (a) tri-layer stack channel (TLSC) (Si–SiGe–Si), (b) double layer stack channel (DLSC) (SiGe–Si), (c) single layer channel (SLC) (Si). The I−V characteristics, subthreshold swing (SS), drain-induced barrier
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Study of the influence of virtual guard ring width on the performance of SPAD detectors in 180 nm standard CMOS technology J. Semicond. Pub Date : 2023-11-01 Danlu Liu, Ming Li, Tang Xu, Jie Dong, Yuming Fang, Yue Xu
The influence of the virtual guard ring width (GRW) on the performance of the p-well/deep n-well single-photon avalanche diode (SPAD) in a 180 nm standard CMOS process was investigated. TCAD simulation demonstrates that the electric field strength and current density in the guard ring are obviously enhanced when GRW is decreased to 1 μm. It is experimentally found that, compared with an SPAD with GRW
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Metallic few-layered 1T-VS2 nanosheets for enhanced sodium storage J. Semicond. Pub Date : 2023-11-01 Liang Wu, Peng Wang, Xingwu Zhai, Hang Wang, Wenqi Zhan, Xinfeng Tang, Qianwen Li, Min Zhou
Metallic few-layered 1T phase vanadium disulfide nanosheets have been employed for boosting sodium ion batteries. It can deliver a capacity of 241 mAh∙g−1 at 100 mA∙g−1 after 200 cycles. Such long-term stability is attributed to the facile ion diffusion and electron transport resulting from the well-designed two-dimensional (2D) electron-electron correlations among V atoms in the 1T phase and optimized
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Study of enhancement-mode GaN pFET with H plasma treated gate recess J. Semicond. Pub Date : 2023-11-01 Xiaotian Gao, Guohao Yu, Jiaan Zhou, Zheming Wang, Yu Li, Jijun Zhang, Xiaoyan Liang, Zhongming Zeng, Baoshun Zhang
This letter showcases the successful fabrication of an enhancement-mode (E-mode) buried p-channel GaN field-effect-transistor on a standard p-GaN/AlGaN/GaN-on-Si power HEMT substrate. The transistor exhibits a threshold voltage (V TH) of −3.8 V, a maximum ON-state current (I ON) of 1.12 mA/mm, and an impressive I ON/I OFF ratio of 107. To achieve these remarkable results, an H plasma treatment was
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Multilayered PdTe2/thin Si heterostructures as self-powered flexible photodetectors with heart rate monitoring ability J. Semicond. Pub Date : 2023-11-01 Chengyun Dong, Xiang An, Zhicheng Wu, Zhiguo Zhu, Chao Xie, Jian-An Huang, Linbao Luo
Two-dimensional layered material/semiconductor heterostructures have emerged as a category of fascinating architectures for developing highly efficient and low-cost photodetection devices. Herein, we present the construction of a highly efficient flexible light detector operating in the visible-near infrared wavelength regime by integrating a PdTe2 multilayer on a thin Si film. A representative device
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Photocatalytic removal of heavy metal ions and antibiotics in agricultural wastewater: A review J. Semicond. Pub Date : 2023-11-01 Jiaxin Song, Malik Ashtar, Ying Yang, Yuan Liu, Mingming Chen, Dawei Cao
In recent years, the treatment of agricultural wastewater has been an important aspect of environmental protection. The purpose of photocatalytic technology is to degrade pollutants by utilizing solar light energy to stimulate the migration of photocarriers to the surface of photocatalysts and occur reduction-oxidation reaction with pollutants in agricultural wastewater. Photocatalytic technology has
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THz plasmonics and electronics in germanene nanostrips J. Semicond. Pub Date : 2023-10-01 Talia Tene, Marco Guevara, Gabriela Tubon-Usca, Oswaldo Villacrés Cáceres, Gabriel Moreano, Cristian Vacacela Gomez, Stefano Bellucci
Germanene nanostrips (GeNSs) have garnered significant attention in modern semiconductor technology due to their exceptional physical characteristics, positioning them as promising candidates for a wide range of applications. GeNSs exhibit a two-dimensional (buckled) honeycomb-like lattice, which is similar to germanene but with controllable bandgaps. The modeling of GeNSs is essential for developing
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High-performance enhancement-mode GaN-based p-FETs fabricated with O3-Al2O3/HfO2-stacked gate dielectric J. Semicond. Pub Date : 2023-10-01 Hao Jin, Sen Huang, Qimeng Jiang, Yingjie Wang, Jie Fan, Haibo Yin, Xinhua Wang, Ke Wei, Jianxun Liu, Yaozong Zhong, Qian Sun, Xinyu Liu
In this letter, an enhancement-mode (E-mode) GaN p-channel field-effect transistor (p-FET) with a high current density of −4.9 mA/mm based on a O3-Al2O3/HfO2 (5/15 nm) stacked gate dielectric was demonstrated on a p++-GaN/p-GaN/AlN/AlGaN/AlN/GaN/Si heterostructure. Attributed to the p++-GaN capping layer, a good linear ohmic I−V characteristic featuring a low-contact resistivity (ρ c) of 1.34 × 10−4
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Forward stagewise regression with multilevel memristor for sparse coding J. Semicond. Pub Date : 2023-10-01 Chenxu Wu, Yibai Xue, Han Bao, Ling Yang, Jiancong Li, Jing Tian, Shengguang Ren, Yi Li, Xiangshui Miao
Sparse coding is a prevalent method for image inpainting and feature extraction, which can repair corrupted images or improve data processing efficiency, and has numerous applications in computer vision and signal processing. Recently, several memristor-based in-memory computing systems have been proposed to enhance the efficiency of sparse coding remarkably. However, the variations and low precision
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Exploration of high-speed 3.0 THz imaging with a 65 nm CMOS process J. Semicond. Pub Date : 2023-10-01 Min Liu, Ziteng Cai, Jian Liu, Nanjian Wu, Liyuan Liu
This paper describes a promising route for the exploration and development of 3.0 THz sensing and imaging with FET-based power detectors in a standard 65 nm CMOS process. Based on the plasma-wave theory proposed by Dyakonov and Shur, we designed high-responsivity and low-noise multiple detectors for monitoring a pulse-mode 3.0 THz quantum cascade laser (QCL). Furthermore, we present a fully integrated
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GaAs-based resonant tunneling diode: Device aspects from design, manufacturing, characterization and applications J. Semicond. Pub Date : 2023-10-01 Swagata Samanta
This review article discusses the development of gallium arsenide (GaAs)-based resonant tunneling diodes (RTD) since the 1970s. To the best of my knowledge, this article is the first review of GaAs RTD technology which covers different epitaxial-structure design, fabrication techniques, and characterizations for various application areas. It is expected that the details presented here will help the
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An 80-GHz DCO utilizing improved SC ladder and promoted DCTL-based hybrid tuning banks J. Semicond. Pub Date : 2023-10-01 Lu Tang, Yi Chen, Kui Wang
An 80-GHz DCO based on modified hybrid tuning banks is introduced in this paper. To achieve sub-MHz frequency resolution with reduced circuit complexity, the improved circuit topology replaces the conventional circuit topology with two binary-weighted SC cells, enabling eight SC-cell-based improved SC ladders to achieve the same fine-tuning steps as twelve SC-cell-based conventional SC ladders. To
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Study of quantum well mixing induced by impurity-free vacancy in the primary epitaxial wafers of a 915 nm semiconductor laser J. Semicond. Pub Date : 2023-10-01 Tianjiang He, Suping Liu, Wei Li, Li Zhong, Xiaoyu Ma, Cong Xiong, Nan Lin, Zhennuo Wang
Output power and reliability are the most important characteristic parameters of semiconductor lasers. However, catastrophic optical damage (COD), which usually occurs on the cavity surface, will seriously damage the further improvement of the output power and affect the reliability. To improve the anti-optical disaster ability of the cavity surface, a non-absorption window (NAW) is adopted for the
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Pressure-dependent electronic, optical, and mechanical properties of antiperovskite X3NP (X = Ca, Mg): A first-principles study J. Semicond. Pub Date : 2023-10-01 Chunbao Feng, Changhe Wu, Xin Luo, Tao Hu, Fanchuan Chen, Shichang Li, Shengnan Duan, Wenjie Hou, Dengfeng Li, Gang Tang, Gang Zhang
Hydrostatic pressure provides an efficient way to tune and optimize the properties of solid materials without changing their composition. In this work, we investigate the electronic, optical, and mechanical properties of antiperovskite X3NP (X2+ = Ca, Mg) upon compression by first-principles calculations. Our results reveal that the system is anisotropic, and the lattice constant a of X3NP exhibits
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The measurement of responsivity of infrared photodetectors using a cavity blackbody J. Semicond. Pub Date : 2023-10-01 Nong Li, Dongwei Jiang, Guowei Wang, Weiqiang Chen, Wenguang Zhou, Junkai Jiang, Faran Chang, Hongyue Hao, Donghai Wu, Yingqiang Xu, Guiying Shen, Hui Xie, Jingming Liu, Youwen Zhao, Fenghua Wang, Zhichuan Niu
For the measurement of responsivity of an infrared photodetector, the most-used radiation source is a blackbody. In such a measurement system, distance between the blackbody, the photodetector and the aperture diameter are two parameters that contribute most measurement errors. In this work, we describe the configuration of our responsivity measurement system in great detail and present a method to
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Fundamentals and applications of photonic waveguides with bound states in the continuum J. Semicond. Pub Date : 2023-10-01 Zejie Yu, He Gao, Yi Wang, Yue Yu, Hon Ki Tsang, Xiankai Sun, Daoxin Dai
Photonic waveguides are the most fundamental element for photonic integrated circuits (PICs). Waveguide properties, such as propagation loss, modal areas, nonlinear coefficients, etc., directly determine the functionalities and performance of PICs. Recently, the emerging waveguides with bound states in the continuum (BICs) have opened new opportunities for PICs because of their special properties in
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Photo-induced flexible semiconductor CdSe/CdS quantum rods alignment J. Semicond. Pub Date : 2023-09-01 Wanlong Zhang, Julian Schneider, Maksym F. Prodanov, Valerii V. Vashchenko, Andrey L. Rogach, Xiaocong Yuan, Abhishek K. Srivastava
The anisotropic absorption and emission from semiconductor CdSe/CdS quantum rods (QRs) provide extra benefits among other photoluminescence nanocrystals. Using photo-induced alignment technique, the QRs can be oriented in liquid crystal polymer matrix at a large scale. In this article, a 2D Dammann grating pattern, within “SKL” characters domains aligned QRs in composite film, was fabricated by multi-step
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A dual-mode image sensor using an all-inorganic perovskite nanowire array for standard and neuromorphic imaging J. Semicond. Pub Date : 2023-09-01 Zhenghao Long, Yucheng Ding, Xiao Qiu, Yu Zhou, Shivam Kumar, Zhiyong Fan
The high-density, vertically aligned retinal neuron array provides effective vision, a feature we aim to replicate with electronic devices. However, the conventional complementary metal-oxide-semiconductor (CMOS) image sensor, based on separate designs for sensing, memory, and processing units, limits its integration density. Moreover, redundant signal communication significantly increases energy consumption