单载流子光电探测器的高速及高饱和功率的研究

High-speed and high-power uni-traveling-carrier photodetector

利用载流子漂移-扩散模型,模拟并分析了InGaAs/InP单载流子光电探测器(Uni-traveling-carrier/UTC-PD)在不同条件下的物理特性及其带宽和饱和特性,结合器件实验结果分析了影响器件高速和高饱和性能的物理机理.结论表明在吸收区采用浓度渐变掺杂和增加InP崖层(cliff layer),可以显著提升器件饱和特性,高入射功率下吸收区电场崩塌是器件饱和的直接因素,直径大于20μm的UTC探测器中RC常数仍是影响带宽的主要因素.论文指出了优化器件结构、提升器件性能的有效方法.

The drift-diffusion theory is adopted to simulate the bandwidth and the saturation characteristics of InGaAs/InP uni-travelingcarrier （UTC） photodetector, According to the experiment results, we analyze the physical mechanisms in high speed and high power UTC photodetector. It is shown that introducing the cliff layer and the gradually doped absorption layer can enhance the saturation characteristic obviously. Electric field collapse in the absorption layer leads to the saturation, and RC constant is still a limitation factor for device with diameter larger than 20 μm. In this paper we point out the effective methods to improve device performance.