PROJECT TITLE :

Dark Current Transport and Avalanche Mechanism in HgCdTe Electron-Avalanche Photodiodes

ABSTRACT:

HgCdTe electron avalanche photodiodes (e-APDs) are widely used for low-flux and high-speed application. To higher perceive the dark current transport and electron-avalanche mechanism of the devices and optimize the structures, we performed correct numerical simulations of this–voltage characteristics and multiplication issue in planar homojunction (p-i-n) HgCdTe APDs. Based mostly on the Okuto–Crowell avalanche model, an efficient physical model has been obtained by concerning the most important generation-recombination processes, like trap-assisted tunneling and band-to-band tunneling (BBT) recombination. Simulated current–voltage characteristics were in good agreement with offered information within the literature, that demonstrates the validity of the proposed model. The origins of dark current in high reverse voltages are jointly dominated by BBT and also the avalanche mechanism. It is proved to be effective for reducing BBT by improving the uniformity of the electrical field distribution across the junction. The electric performance of p-i-n e-APD will be improved by optimizing the APD structure, like eliminating the sharp corners of junctions, light-weight doping, and the suitable thickness in multiplication region. Our works provide a good deal of insight into the fundamental carrier transport processes involved in HgCdTe e-APDs.