Low-Temperature a-Si:H/GaAs Heterojunction Solar Cells

We propose a novel hydrogenated amorphous silicon (a-Si:H)/GaAs heterostructure for photovoltaic solar cells. The structure has two key advantages: 1) low-temperature processing and 2) a relatively low cost of cell fabrication compared with conventional junction structures that require epitaxial growth. We investigate the impact of different hydrogen dilution levels used during a-Si:H deposition on the electrical characteristics of heterojunction GaAs solar cells. It is interesting to note that epitaxial growth of silicon on GaAs occurred when relatively high hydrogen dilution levels were used. The prospect of silicon epitaxy in improving the cell performance is discussed.