Solution-Based Silicon in Thin-Film Solar Cells

Solution‐based semiconductors give rise to the next generation of thin‐film electronics. Solution‐based silicon as a starting material is of particular interest because of its favorable properties, which are already vastly used in conventional electronics. Here, the application of a silicon precursor based on neopentasilane for the preparation of thin‐film solar cells is reported for the first time, and, for the first time, a performance similar to conventional fabrication methods is demonstrated. Because three different functional layers, n‐type contact layer, intrinsic absorber, and p‐type contact layer, have to be stacked on top of each other, such a device is a very demanding benchmark test of performance of solution‐based semiconductors. Complete amorphous silicon n‐i‐p solar cells with an efficiency of 3.5% are demonstrated, which significantly exceeds previously reported values. Solution‐based semiconductors are a promising new material class in thin‐film electronics. So far, the quality of the device made of such material has been rather poor. Here, solar cells made of solution‐based silicon with an efficiency of 3.5%, exceeding previous results by a factor of seven, are reported. This may pave the way for development of industrial applications.