Determination of the electric field at interfaces in amorphous-silicon devices using time-of-flight measurements

The built-in electric field in hydrogenated amorphous silicon (a-Si:H) Mo-Schottky diodes is estimated using voltage transient measurements generated by a sophisticated time-of-flight or time-resolved photoconductivity experiment with a rather high time resolution of 1 ns. The actual determination of the electric field is done by inverse modeling. The simulator (forward model) for the voltage transient is based on the complete set of transport equations for the charge carriers, including surface recombination. The significance of the diffusion and surface recombination is clearly shown by comparing simulated and measured voltage transients