Low-frequency photocurrent noise in semiconductors: Effect of nonlinear current-voltage characteristics

A current noise model for planar metal-semiconductor-metal photodetectors i s proposed, which allows one to account for the low-frequency excess-noise behavior measured in several semiconductor devices. According to the propos ed model-based on a multiplicative noise mechanism-the photocurrent noise p ower can be directly related to the carrier density and to the photogenerat ion level. Moreover, in the absence of potential-barrier fluctuations, the standard 1/n behavior of the simple g-r noise model is recovered. (C) 2001 American Institute of Physics.