Study and characterization of semiconductor junctions for photovoltaic applications by contactless methods

a-Si:H/c-Si junctions were investigated by contactless photoconductivity measurements in the microwave frequency range. The dependence of the junction properties on the thickness of the a-Si:H films was determined via a characterization by the interface recombination velocity at the junction at a fixed injection level. It is shown that the differential recombination rate at the junction as a function of the injection level yields information on band bending and interface defect density. The separation and collection of excess charge carriers at the junction was observed with time-resolved measurements.