Self-cleaning transparent pn junction in CuAlO2/WO3 via high entropy perovskite oxide La(Cu0.2Cr0.2Ni0.2Fe0.2Co0.2)O3 transition layer for enhanced photovoltaic conversion

The self-cleaning transparent pn junction in CuAlO2/WO3 via high entropy perovskite oxide La(Cu0.2Cr0.2Ni0.2Fe0.2Co0.2)O3 transition layer is prepared by the multiple sol–gel-annealing method. The CuAlO2/La(Cu0.2Cr0.2Ni0.2Fe0.2Co0.2)O3/WO3 pn junction exhibits high transmittance of ∼85–90 %, remarkable photovoltaic enhancement of ∼6.2 × 103 folds (PCE of ∼1.19 %), stable output in 5 months’ cycle and decent self-cleaning performance via simple cleanout. It can be mainly attributed to the modification of multifunctional high entropy perovskite oxide solid solution La(Cu0.2Cr0.2Ni0.2Fe0.2Co0.2)O3 nanoparticles, besides the appropriate Fermi level and high quantum yield can improve the carrier kinetic equilibrium for balancing transparency and photovoltaic conversion, it can also improve extra carrier injection by the charge compensation and promote carrier driving by the lattice driving force, meanwhile achieving self-cleaning via the hydrophobicity of WO3.