Defects and transport in a-Si:H/c-Si heterojunctions

Abstract We have investigated amorphous silicon/crystalline silicon np and pn heterojunction devices with transport and capacitance measurement techniques. The devices consist of doped n-type or p-type hydrogenated amorphous silicon deposited on p-type or n-type float-zone crystalline silicon wafers. Low temperature (100 K) photocurrent measurements in conjunction with numerical simulations indicate a large conduction band offset at the interface between the two materials. We show experimentally and with numerical simulation that defects at the heterojunction interface affect the low frequency capacitance and the electronic transport in the devices.