Spin dependent recombination in CdTe/CdS solar cells

We report upon a new analytical approach for cadmium telluride/cadmium sulfide photovoltaic cells that is directly and exclusively sensitive to recombination center defects within the devices. The apparatus required to carry out these measurements is relatively straightforward and the response is robust. The measurements exploit the fact that recombination events through deep level defects are spin dependent and the presence of relatively small magnetic fields can alter spin dependent phenomena. The measurement involves small changes in the recombination current as a function of magnetic field when device current is strongly affected by recombination events.