Optically transparent and electrically conductive NiO window layer for Si solar cells

•Electrically conductive and optically transparent NiO was applied.•NiO window layer efficiently transmit visible light with selective blocking of UV.•Functional NiO window-embedding solar cell provides significant improvements.

Nickel oxide (NiO) material has been functionally applied for Si solar cells. Optically transparent and electrically conductive NiO was used as a window layer for Si solar cells to provide a relatively high efficiency of 15.37%. An optically transparent NiO layer was coated onto Si by large-area applicable sputtering deposition to give good crystalline structure. NiO-coating on Si spontaneously reduces the light reflection for visible range light, resulting in the improved current profiles. Due to the electrically low sheet resistance, the NiO-coating design is effective to improve the open circuit voltage and fill factor of solar cells. The optical and electrical benefits of NiO would provide a route of improvement for various photoelectric devices, including solar cells.