A new-type inorganic [KNbO3]0.9[BaCo1/2Nb1/2O3-δ]0.1perovskite oxide as sensitizer for photovoltaic cell

Abstract

An electrode with [KNbO3]0.9[BaCo1/2Nb1/2O3–δ]0.1 (KBCNO) perovskite oxide as sensitizer and well-aligned TiO2 nanorod arrays is prepared via conventional standard solid-state synthesis method, followed by pulsed laser deposition technique for the first time. Enhanced absorption in visible light region is observed for KBCNO@TiO2 NRs photoelectrode, which is mainly because the inserted Co 3d electronic states can hybridize with O 2p states in the gap of KBCNO, reducing the band gap to 1.90 eV. Additionally, the oxygen vacancies existing in KBCNO can not only serve as photoinduced charge traps and adsorption sites but also prevent recombination of photoinduced electron–hole, giving rise to enhanced separation of photogenerated electron–hole pair and leading to an improved performance in solar energy conversion. The KBCNO@TiO2 NRs photoelectrode exhibits an energy conversion efficiency of 0.183% under one sun illumination. This work provide further insight for improving the efficiency of utilization of solar energy by using a new composite perovskite oxides material, which may be promising rational categories of material for solar conversion and storage devices.