Surface Band Bending Effects on Photoluminescence Intensity in n-InP Schottky and MIS Diodes

Abstract

Surface band bending effects on the photoluminescence (PL-) intensity in n-InP Schottky and MIS diodes were studied. The bias dependence curve of the PL-intensity for n-InP is quite different from those obtained for Si, Ge and GaAs with large surface recombination velocity. Remarkable depression and enhancement of the PL-intensity were observed in n-InP with application of reverse and forward bias voltages. The maximum PL-intensity was achieved at the flat-band bias condition in Schottky diodes. In MIS diodes, the PL-intensity increased when the forward bias voltage was more than the flat band voltage. PL-intensity variation with surface band bending for Schottky and MIS diodes can be explained well using a surface dead layer model in the depletion condition and a surface excess carrier model in the accumulation condition.