Performance Analysis of a Ge-on-Si Resonant Cavity Enhaced Schottky Photodetetor for Optical Communication at 1.55 μ m

In this paper, performance of a Ge-on-Si Resonant-Cavity-Enhanced (RCE) Schottky Photodetector at 1.55_m has been investigated considering the effects of carrier confinements at the Si/Ge heterointerface. The transit-time delay and loss of carriers by recombination have been included in the model to calculate photocurrent, bandwidth, quantum efficiency and bandwidth-quantum efficiency product of the photodiode. Results show that the effect of carrier confinements plays a significant role on the bandwidth as well as quantum efficiency of the photodetector at lowbias. Possible optimum designs of the photodetector at different biases have been suggested in the paper. Noise equivalent bandwidth, dark current, and minimum detectable power are shown for different dimensions of the photodiode and biases indicating the role of heterointerface confinement of carriers.