Excess current and luminescence noise of P-N junctions in GaP

Abstract

The low-frequency fluctuations of the forward current and of the electroluminescence intensity in GaP diodes as well as the correlation between them have been investigated. The current noise appears to be excess noise of the 1/ f type in the whole frequency region and in the whole range of the forward biases under investigation. The component of the excess noise has been discovered in the luminescence noise as well, and this component appears to be fully correlated with the current noise. A simultaneous analysis of the relation between the excess-current noise and the luminescence noise reveals that the sources of the excess-current noise in the p-n junction which are usually considered ( i.e, the fluctuations in the rate of the surface recombination, the fluctuations of the contact resistance, the fluctuations of the exchange processes between c- and v-band and the different levels in the space-charge region) are not the dominant noise sources in the GaP diodes investigated. A possible connection between the observed excess noise and the temperature fluctuations in the vicinity of the p-n junction has been discussed as well.