A self-cleaning transparent pn junction in perovskite SrTiO3 QDs modified CuGaO2/Zn2SnO4 nanoarrays is prepared via the hydrothermal-solgel-surface plasma (SP) method. The CuGaO2/SrTiO3 QDs/Zn2SnO4 exhibits transmittance of ∼85%–90%, photovoltaic enhancement of ∼1.8 × 103-folds (photovoltaic conversion efficiency of ∼1.25%), stable output in 5 months, and good hydrophobicity (contact angle of ∼138.1°). The main reasons are mainly attributed to the SrTiO3 QDs and SP modification; besides the appropriate Fermi level and high quantum yield can improve the carrier kinetic equilibrium for balancing transparency-photovoltaic conversion efficiency, the SP modification can enhance the solar and carrier efficiency further, meanwhile achieving self-cleaning. Additionally, the CuGaO2 orderly nanoarrays can release stress, increase solar efficiency, and promote carrier transportation, in order to balance the structural stability, transparency, and photovoltaic efficiency.