Cu2O thin films as the color-adjusting layer in semi-transparent a-Si:H solar cells

We investigated penetration-type semi-transparent hydrogenated amorphous silicon (a-Si:H) solar cells that incorporated cuprite (Cu2O) thin films, deposited by radio frequency magnetron sputtering, as the color-adjusting layer. Depending on the arrangement of the Cu2O and transparent conductive oxide layers in the cells, the cells could be classified as either inner-type or outer-type. By simulating and experimentally measuring the reflectance of both types of cells, it was found that the optical interference in the two cells had a more significant effect on the short-circuit current density than did the thickness of the incorporated Cu2O films. We fabricated a-Si:H cells whose transparency and color could be controlled simultaneously. This technique of fabricating a-Si:H cells that exploit the phenomenon of interference can be used to realize cells that exhibit different colors.