The electric field and dopant distribution in p-i-n structures observed by ionisation potential (dopant contrast) microscopy in the HRSEM

摘要

The method of ionisation potential (dopant contrast) microscopy in the HRSEM is applied to the study of the electric field distribution in p-i-n structures used as quantum well solar cells. Our results show a secondary electron signal which varies between the different layers, being greatest in the p-type and smallest in the n-type regions respectively. The stacks of 8 nm wide quantum wells and their corresponding barriers are clearly distinguished in the intrinsic region of the devices. In-situ observation of reverse biased structures has been performed to determine the effect of bias on the potential distribution within the devices.