A photodetector that utilizes the phase-changing material Ge2Sb2Te5 (GST) integrated with a silicon on insulator (SOI) waveguide is designed and analyzed in the wavelength (λ) range of 1500 to 1600 nm for telecommunication and optical fiber communication. The analysis of simulated structure reveal that GST is a promising material for photodetection applications due to phase-change property on a nanoscale, excellent absorption (with an absorption coefficient of ∼106 cm − 1), lower bandgap of 0.63 eV in the amorphous phase, and 0.53 eV in the crystalline phase, tunability, and high phase stability. The photodetector structure consists of an SOI substrate, silicon waveguide, GST layer as phase changing material, and gold (Au) to make contacts. The photodetector’s optical and electrical parameters, such as electric field distribution of carrier generation rate (G), absorbed power (Pabs), dark current (Idark), photocurrent (Iph), and responsivity (R), are analyzed for both the amorphous (a-GST) and crystalline (c-GST) phases. The results demonstrate the potential of GST material to design high-performance photodetectors for various applications. The highest resistivity of 2.29 A / W is achieved for a-GST at λ = 1550 nm, with a bias voltage range of 0.5 to 2.5 V. The maximum absorption is observed in the amorphous phase as compared to the crystalline phase of GST. The calculated values of Iph and Idark are 0.24 mA and 78.54 μA for a-GST and 0.12 mA and 15.71 μA for c-GST, respectively. The optoelectrical behavior of GST-based photodetector on SOI waveguide demonstrates their potential application in photonic integrated circuits. Our work proposes an approach for using GST in photodetectors and analyzes both phases of GST that have not been explored before. Therefore, for the viability of the reported work, a detailed comparison is also presented with other simulated structures and found that the proposed device provided excellent results with low bias voltage.

中文翻译：

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波导集成Ge2Sb2Te5可调谐光电探测器仿真

采用与绝缘体上硅 (SOI) 波导集成的相变材料 Ge2Sb2Te5 (GST) 的光电探测器在 1500 至 1600 nm 的波长 (λ) 范围内进行设计和分析，用于电信和光纤通信。模拟结构分析表明，GST 具有纳米级的相变特性、优异的吸收性能（吸收系数为 ∼106 cm − 1）、非晶相的带隙较低（0.63 eV），是一种很有前景的光电探测材料。结晶相0.53 eV，可调谐性和高相稳定性。光电探测器结构由 SOI 基板、硅波导、作为相变材料的 GST 层以及用于接触的金 (Au) 组成。光电探测器的光学和电学参数，对非晶态 (a-GST) 和晶态 ( c-GST）阶段。结果证明了 GST 材料为各种应用设计高性能光电探测器的潜力。a-GST 在 λ = 1550 nm 处实现了 2.29 A/W 的最高电阻率，偏置电压范围为 0.5 至 2.5 V。与 GST 的晶相相比，在非晶相中观察到最大吸收。a-GST 的 Iph 和 Idark 计算值分别为 0.24 mA 和 78.54 μA，c-GST 的 Iph 和 Idark 计算值分别为 0.12 mA 和 15.71 μA。SOI 波导上基于 GST 的光电探测器的光电行为证明了它们在光子集成电路中的潜在应用。我们的工作提出了一种在光电探测器中使用 GST 的方法，并分析了以前从未探索过的 GST 的两个阶段。因此，为了报告工作的可行性，还与其他模拟结构进行了详细比较，发现所提出的器件在低偏置电压下提供了出色的结果。