Generation-Recombination Noise in a-Si:H Studied by Device Simulations

摘要

An attempt is made to interpret low-frequency noise measured in a-Si:H n-i-n devices based on the assumption that the noise is due to generation-recombination (g-r) processes. The interpretation is based on a spatial distribution of recombination lifetimes of electrons obtained with the help from the AMPS-1D device simulation program. These lifetimes have the same order of magnitude as that of the noise observed. Further, a distribution of lifetimes naturally results from band bending. Simulations of noise spectra are obtained by multiplication of a phenomenological weight factor to the Lorentzian spectral contribution corresponding to the local electron lifetime. There are, however, two problems with this interpretation: (ⅰ) we were not able to come up with a reasonable noise description, where the relatively long electron lifetimes were not overshadowed by much shorter times (ⅱ) the current description, where variance is included in a weight factor, is still incomplete, and therefore we can not explain the shape of the weight factor yet.