We have studied the nonlocal photovoltaic response to a laser beam in CdTe/CdS solar cells. The laser-generated plasma is shown to spatially decay over a considerable distance that depends on the device lateral resistance and laser beam power. This affects open circuit voltage far from the laser spot. For the case when the lateral resistance is dominated by the transparent conductive oxide (in completed devices), it is shown that the characteristic decay length may be as long as 1 m. For the alternative case of unfinished devices that do not have a metal layer, the semiconductor layer sheet resistance dominates the nonequilibrium plasma spreading, and the characteristic decay length falls into the range of tenths of a millimeter. Also associated with such nonlocal response are features in photoluminescence mapping, where different excitation powers lead to different map topologies. We have developed a theory that expresses the effects of laser-generated plasma spreading in terms of the semiconductor film photovoltaic parameters.
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