Model study of fluctuations and switching in amorphous semiconductors

The model developed by Ma for the initiation of threshold switching is used as the basis for a master equation description of the fluctuation spectrum of the number of carriers. The system size expansion is used to derive explicit expressions for the fluctuation spectrum in terms of the parameters of the model. It is shown that the study of the power spectra of current fluctuations about stationary states is a useful way of investigating the physical mechanisms responsible for switching.