Photovoltaic properties of n-Type nanocrystalline-FeSi2/intrinsic-Si/p-Type Si heterojunctions fabricated by facing-targets DC sputtering

Nanocrystalline FeSi₂ (NC-FeSi₂) thin films were grown on Si(111) substrates by facing-targets DC sputtering at room temperature using FeSi₂ targets. The NC-FeSi₂ films showed hopping conduction behavior, which was confirmed by the temperature dependence of the electric conductivity. n-Type NC-FeSi₂/p-type Si and n-type NC-FeSi₂/i-Si/p-type Si heterojunctions were prepared to be employed as photovoltaics. For the p-i-n heterojunctions, i-Si thin layer reduced the leakage current and improved photovoltaic properties as compared to the p-n heterojunctions. This improvement might be due to the i-Si layer that acts as a leakage blocking layer rather than a light absorption layer.