Improvement of Voc and Jsc in CuInGaSe2 solar cells using a novel sandwiched CuGa/CuInGa/In precursor structure

In this study, a novel structure using a sandwiched CuGa/CuInGa/In precursor layer is employed for improving the Voc and Jsc of a CIGS solar cell. The addition of a CuGa layer on the surface of CuInGa precursor enhanced the Ga concentration in the space charge region and thus enhanced the Voc by about 18.2%. The addition of an In layer to the bottom of CuGa/CuInGa/In precursors increased the absorber solar spectrum edge and thus improved the Jsc by about 14%. The device conversion efficiency using this novel precursor structure was found to increase by about 50% from 6.2% to 9.5%.