Band offsets and transport mechanisms of hydrogenated nanocrystalline silicon/crystalline silicon heterojunction diode: Key properties for device applications

We have studied the electrical properties of hydrogenated nanocrystalline silicon/crystalline silicon heterojunction diode, focusing on the band offsets and electron transport mechanisms. Capacitance-voltage (C-V) analysis reveals that the band discontinuity mainly exists on the valence-band side, and an interface charge density on the order of 1011cm−2 is estimated via the numerical C-V matching technique. Temperature- and bias-dependent transport mechanisms have been clarified by dark current-voltage-temperature measurements, and the extracted parameters indicate a transition from nontunneling to tunneling dominant transport from 350to20K.