Upright dome nanostructure for enhanced light absorption in thin-film silicon solar cells

Abstract

The crystalline silicon (c-Si) solar cells with light-trapping structures can enhance light absorption within the semiconductor absorber layer, especially in thin-film crystalline silicon (c-Si) solar cells. Here we demonstrate that a dome surface light-trapping scheme for c-Si thin films, fabricated via laser interference lithography and chemical wet etching process, significantly enhances the light absorption within the c-Si layer. In this paper, we demonstrate its good antireflection ability and light trapping performance. As a result, an overall reflection down to 5.35% in the spectrum range of 400-1000nm wavelength was achieved, which is 7.8% lower than inverted pyramid without additional nitride coatings. To quantitatively evaluate the light trapping performance of the textures, the enhancement factor in the dome case is 45%, while for the pyramid texture the AE factors is only around 39.7%. In addition, the absorbed photocurrent density is 14.38 mA/cm2 for a 2 μm silicon absorber layer at an incidence angle of 0°, which is 1.32 mA/ cm2 higher than inverted pyramids. The proposed structure has the potential to play a key role in thin film solar cells.