EVALUATION OF LOW DARK CURRENT INSB PHOTOVOLTAIC DETECTORS

This paper reports on the fabrication and evaluation of high-quality InSb photovoltaic detectors. Etchpits on the [111] face of the InSb substrates were studied. This distribution usually shows a "T" shape. Detectors fabricated in an etchpit rich region show a large dark current while those from a pit-free region show low dark current. This is because the tunneling current becomes dominant at different reverse bias levels for devices fabricated in the different regions. We also present what are the first reported effects of a reverse injection current on the performance of these detectors. The breakdown voltage of the detector increases after the injection process. However, the dark current at small reverse bias (-200 mV) increases and then decreases with an increase of the reverse injection current. This result may be due to hole trapping in the passivation layer during the injection process.