Light Trapping in Ultrathin CIGS Solar Cell With Absorber Thickness of 0.1 μm

Commercial thin-film solar cells have a thickness of absorber layer in the range 1-2.5 μm. As the thickness of the absorber layer is reduced below 1 μm, light absorption reduces dramatically which in turn reduces the commercial viability of the solar cell. Here, we improve on previously demonstrated light trapping techniques to suggest two configurations which can potentially be employed to reduce thickness of the absorber layer from 1 to 0.1 μm while retaining the level of light absorption. While we demonstrate our results for the particular case of CIGS thin-film solar cell, the techniques are equally applicable to thin-film cells made of other absorber materials.