Separated-absorption-multiplication 4H-SiC avalanche photodiodes with adjustable responsivity and response time

摘要

4H-SiC based avalanche photodiodes (APD) with a small multiplication region onto a large absorption region, which can be regarded as a particular separated-absorption-multiplication structure, are proposed and their optoelectronic performances are modeled. The avalanche breakdown voltage, energy band diagram, spectral responsivity and response time of the devices are found to be dependent on the area of multiplication region. The performance of the device could be similar to a conventional separated-absorption-multiplication APD or p-i-n diode by designing various multiplication areas. Characteristics of the APD are fully studied and explained by the analysis of energy band diagrams of the devices. (C) 2015 The Japan Society of Applied Physics