Potential of amorphous silicon for solar cells

This paper reviews recent developments in the field of amorphous-silicon-ba sed thin-film solar cells and discusses potentials for further improvements . Creative efforts in materials research, device physics, and process engin eering have led to highly efficient solar cells based on amorphous hydrogen ated silicon. Sophisticated multijunction solar cell designs make use of it s unique material properties and strongly suppress light induced degradatio n. Texture-etching of sputtered ZnO:Al films is presented as a novel techni que to design optimized light trapping schemes for silicon thin-film solar cells in both p-i-n and n-i-p device structure. Necessary efforts will be d iscussed to close the efficiency gap between the highest stabilized efficie ncies demonstrated on lab scale and efficiencies achieved in production. In case of a-Si:H/a-Si:H stacked cells prepared on glass substrates, signific ant reduction of process-related losses and the development of superior TCO substrates on large areas promise distinctly higher module efficiencies. A discussion of future perspectives comprises the potential of new depositio n techniques and concepts combining the advantages of amorphous and crystal line silicon thin-film solar cells.