High performance p-type transparent LaCuOS thin film fabricated through a hydrogen-free method

Abstract It is a crucial and also well-known challenge to develop p-type transparent semiconducting oxides (TSOs) for future optoelectronics including transparent electronics. In this work, a novel hydrogen-free thin film fabrication method is proposed and succeeded to prepare high quality single phase p-type oxychalcogenide LaCuOS thin film in a safe, economically efficient and easy way. It differs from conventional processes for oxychalcogenide films that involve the usage of toxic and hydrogen-containing H2S gas as well as the tedious and highly costly sputter targets preparation. Instead, we combine a unique co-sputtering of La2O3 and Cu and sulfurization process to make the oxychalcogenide thin films free from any n-type hydrogen doping influence. The achieved p-type electrical conductivity of 0.3 S cm−1 is much higher than other polycrystalline LaCuOS films and among the best non-doped p-type TSOs reported so far. Furthermore our films also demonstrate great room temperature photoluminescence. The success of this newly developed thin film fabrication process also lays the groundwork to the fabrication of other highly conductive p-type oxychalcogenides thin films.