Fabrication of ZnO/CuBr1-xIx microstructural transparent solar cells with buffer layer

Transparent solar cells (TSCs) are invisible, landscape-harmonized power generation devices that can be installed on a large number of surfaces. Herein, ZnO/CuBr1-xIx (CuBrI) microstructural TSCs with ZnO nanorods (NR) were fabricated via a solution process; the ZnO NRs were used to decrease carrier loss. A ZnO or MgO buffer layer (BL) was introduced between ZnO and CuBrI to improve the open circuit voltage (VOC). The BLs significantly improved the VOC by reducing the leakage current. Moreover, owing to the suppression of carrier recombination near the p-n junction interface, the short circuit current density (JSC) of the TSC with MgO BL increased, and the VOC improved further. The TSC with MgO BL exhibited the highest power density of 7.3 nW cm−2 with a VOC of 42 mV, JSC of 0.64 μA cm−2, fill factor of 26.7%, and transmittance of over 70% across a wavelength range greater than 500 nm.