Effect of contact barrier height on performances of BaSi2 heterojunction and homojunction solar cells

The effects of contact barrier height on performances of Si/BaSi 2 p–n heterojunction, BaSi 2 p–n homojunction and Si/BaSi 2 /Si p–i–n heterojunction were numerical calculated. Band energy diagram, built-in electric field, carrier generation and carrier transportation distributed in the devices are comprehensively investigated. BaSi 2 p–n homojunction solar cells are very sensitive to front contact barrier height due to the high light absorption coefficient of front p-BaSi 2 layer. Si/BaSi 2 p–n heterojunction and BaSi 2 p–n homojunction solar cells with donor concentration [Formula: see text] less than [Formula: see text] are apparently affected by back contact barrier height. The ideal [Formula: see text]-Si/BaSi 2 /[Formula: see text]-Si p–n solar cell achieves a high [Formula: see text] of 1.131 V, suggesting a promising and alternative structure to gain excellent BaSi 2 -based solar cells once the Urbach tail states and defects can be effectively eliminated. The results help to fundamentally understand operation mechanism and provide intuitive guidance for achieving high-efficiency BaSi 2 solar cells.