Transport Properties of Amorphous Silicon / Silicon Oxide Heterostructures

Abstract

ABSTRACTThe transport of excess carriers in glow-discharge deposited a-Si:H/insulator heterostructures has been studied by time-of-flight and xerographic discharge techniques. Efficient injection of photocarriers from a-Si:H into, and transport through, relatively thick SiOx:N:H has been achieved. A mobility-lifetime product approaching 18−6 cm2V−1 is found for electrons in SiOx:N:H, and time resolved measurements indicate a room temperature mobility of 5×10−6 cm2v−1s−1 at a field of 2×104 Vcm−1, suggesting an electron lifetime of the order of 8.2 seconds. The results are contrasted with transport measurements on thermally grown SiO2 on Si and a transport model involving hopping through defect states within the gap of SiOx:N:H is discussed.