In this study, we conducted finite difference time domain simulation investigations of the transient responses of silicon-on-insulator waveguide-based vertical photodetectors using the phase-change material Ge₂Sb₂Te₅ (GST) as a sensing element on the Si core. The charge transport characteristics comprising the carrier and displacement current were comprehensively studied based on variations in the dimension, pulse width, and frequency by solving the drift-diffusion model under constant biased conditions. The dynamic behaviors of two stable GST phases comprising amorphous (aGST) and crystalline (cGST) were compared in terms of the peak amplitude, peak arrival time, and rate of change in the current for both phases. The cGST based device was much faster, with the lowest peak arrival time of 21.5 ps and rate of arrival of 56.5 μA/ps at a wavelength of 1150 nm. The lowest value peak arrival time was 22 ps with a slope of 4 μA/ps for the aGST based device at a wavelength of 1850 nm. The results showed that cGST is suitable for lower wavelengths whereas aGST is appropriate for higher wavelengths in the near-infrared operating range to obtain instant dynamic response, thereby allowing the production of a tunable photodetector with a phase-change material.

在这项研究中，我们使用相变材料Ge ₂ Sb ₂ Te ₅（GST）作为硅芯上的传感元件，对基于绝缘体上硅的波导的垂直光电探测器的瞬态响应进行了时差有限差分仿真研究。通过在恒定偏置条件下求解漂移扩散模型，基于尺寸，脉冲宽度和频率的变化，对包括载流子和位移电流在内的电荷传输特性进行了全面研究。两个稳定GST相包含无定形（动态行为一个GST）和结晶（Ç比较了两个阶段的峰值幅度，峰值到达时间和电流变化率。基于c GST的设备要快得多，在1150 nm波长处的最低峰值到达时间为21.5 ps，到达速度为56.5μA/ ps。最低值峰到达时间为22皮秒与4μA/ PS为的斜率一个在1850纳米的波长基于GST设备。结果表明，Ç GST适合于更低的波长，而一个GST是适合于近红外操作范围更高的波长以获得即时动态响应，从而允许生产具有相变材料的可调谐光检测器的。