Photoconductivity of CaH2-reduced BaSnO3 thin films

Abstract

Incorporation of foreign chemical elements in oxides can significantly alter their optoelectronic performances, and thus it is widely used to seek new transparent conductive oxides. Chemical-doping BaSnO₃ systems, like La-doped BaSnO₃, are of increasing interest with extremely high electrical mobility and excellent oxygen stability, exhibiting the potential application in next-generation all-perovskite optoelectronic devices. In this work, hydrogen was introduced into BaSnO₃ through CaH₂ reduction of BaSnO₃ thin films, and the electrical properties, as well as the photo-response behavior, were investigated. Secondary ion mass spectroscopy demonstrated the uniform distribution of hydrogen within the BaSnO₃ thin film. The addition of hydrogen greatly enhanced the conductivity of the BaSnO₃ thin film, exhibiting a carrier concentration ∼8.04 × 10¹⁹ cm⁻³ and mobility ∼9.52 cm² V⁻¹ s⁻¹ at 300 K, and thus resulted in a fast relaxation process in the transient photoconductivity, which was characterized by a double exponential function indicating two physical contributions.