Forward-tunneling current voltage characteristics of HgCdTe p-on-n photodiodes

Current-voltage characteristics of narrow-gap HgCdTe p-on-n photodiodes at different temperatures have been investigated. Forward tunneling current is seen in a certain forward bias region. A constant-current mode was also used to identify the trap-assistant tunneling, and the results show this forward tunneling current influences the zero bias resistance. Ideality factors, calculated from current-voltage experimental data, show a peak in the intermediate forward bias region. The height of peak in ideality factor decreases as the temperature increases. This peak is thought due to the multi-step tunneling current.