Effect of textured tin oxide and zinc oxide substrates on the current generation in amorphous silicon solar cells

The authors evaluate material properties of a number of textured SnO₂ and ZnO substrates and their effect on current generation in a-Si. Most of these TCOs have been used by others for a-Si solar cell research or module fabrication. Bulk optoelectronic and structural properties are reported for seven TCO films with haze from 1 to 14%. Their results show that increasing haze above ~5% has limited effectiveness for increasing the generation at long wavelengths. In presently available textured ZnO, current generation is about 0.6 mA/cm ² greater than in textured SnO₂. There may be greater advantages to using ZnO in multijunction devices since much thinner i-layers may be used to give the same short-circuit current with improved stability, shorter deposition time and less GeH₄ usage