Structural design of BaSi2 solar cells with a-SiC electron-selective transport layers

Abstract Sputter-deposited polycrystalline BaSi 2 films capped with a 5 nm thick a-SiC layer showed high photoresponsivity. This means that the a-SiC layer functions as a capping layer to prevent surface oxidation of BaSi 2 . Based on the measured absorption edge, the electron affinity of the a-SiC layer, and the work function of the TiN layer, the a-SiC is considered to act as an electron transport layer (ETL) for the BaSi 2 light absorber layer/a-SiC interlayer/TiN contact structure in a BaSi 2 solar cell. Using a 10 nm thick p + -BaSi 2 layer as a hole transport layer, we investigated the effect of the BaSi 2 /a-SiC layered structure on the device performance of a BaSi 2 -pn homojunction solar cell by a one-dimensional device simulator (AFORS-HET v2.5). The a-SiC ETL effectively separates photogenerated carriers and allows transport of electrons while blocking holes to achieve an efficiency of 22% for a 500 nm thick BaSi 2 light absorber layer.