INVESTIGATION OF P-I-N SOLAR-CELL EFFICIENCY ENHANCEMENT BY USE OF MQW STRUCTURES IN THE I-REGION

The effects of CdTe quantum wells in CdMnTe Schottky junctions and p-i -n structures have been explored with a view to determining the improv ements in photovoltaic energy conversion efficiency which might be ach ieved in such devices. Spectral response measurements have demonstrate d (i) that the presence of the wells successfully extends the range of absorbed photons to lower energies and (ii) that, under normal ambien t temperature conditions, the photostimulated carriers have a high pro bability of escaping from the wells, thereby contributing to the photo generated current. Measurements at lower temperatures have indicated a reduced quantum efficiency, consistent with theoretical prediction as suming carrier escape from the wells to be a predominantly thermally a ctivated process.