Lf. Marsal et al., ELECTRICAL-PROPERTIES OF PECVD AMORPHOUS SILICON-CARBON ALLOYS FROM AMORPHOUS-CRYSTALLINE HETEROJUNCTIONS, DIAMOND AND RELATED MATERIALS, 6(10), 1997, pp. 1555-1558
Heterojunction diodes fabricated by plasma enhanced chemical vapour de
position of n-type amorphous silicon carbide on p-type crystalline sil
icon are analysed by measuring their current-voltage characteristics.
Two carrier transport mechanisms are believed to be at the origin of t
he forward current. At low bias voltage, the current is due to recombi
nation in the amorphous side of the space charge region, while at high
er voltages, the current becomes space charge limited. At reverse bias
, the current can be explained by tunnelling models. The space charge
limited currents in these heterojunctions have been used to determine
the density of states in the n-type a-Si1-xCx:H gap. The results show
the increase in localized states when approaching the conduction band
edge. (C) 1997 Elsevier Science S.A.