Improved Laplace transform method to determine trap densities from transients: application to ZnO and films

Abstract

A simple method is proposed for analysis of non-exponential transients based on the Laplace transform of a transient. It is useful for analysis of any non-exponential transient to obtain information on the density of localized states distribution. The improvement involved a correction of the tail regions of the distribution to provide a close fit between the simulated and experimental transient. By testing it on a number of different types of simulated transients, it was possible to ascertain the scope of this method. In principle this analysis can be applied to a variety of physical processes. In the present case it was applied to experimental photoconductivity transients for polycrystalline ZnO and films deposited by spray pyrolysis.