Simulation and Analysis of Field-dependent Measurements for Different a-Si:H and nc-Si:H Samples

Abstract

Abstract: A simulation based on the method of weighted residuals is conducted to reproduce the available experimental data of field-dependent steady-state photocarrier grating (SSPG). Different samples of amorphous hydrogenated silicon (a- Si: H) and nanocrystalline hydrogenated silicon (nc- Si: H) thin films prepared by plasma-enhanced chemical vapor deposition (PECVD) technique are employed in the simulation. The reproduced field-dependent data are optimized using 2 indicator. Approximate and correct values of important photoelectronic parameters are extracted from the analysis of results. The analysis reveals values of small-signal response lifetime and electron and hole mobilities comparable to the values obtained from other methods’ applications. The difference between approximate and correct values lies within the experimental error of 5% with one exception regarding a poorly conductive sample. Moreover, the extracted values of both ambipolar diffusion length and charge carrier density are found reasonable and justify the success of the application of the adopted method on the chosen samples. Keywords: Electronic transport phenomena in thin films; Charge carriers: generation, recombination, lifetime, trapping, mean free paths; Photoconduction and photovoltaic effects.