1.37×10² S·cm^-1 p-type conductivity LaCuOS films with a very wide optical transparency window of 400-6000 nm

The absence of highly conductive p-type transparent semiconductors has blocked the development of transparent p-n junction devices and electronics, and it is a well-known challenge to achieve highly conductive p-type transparent materials. In this paper, we report the achievement of large area p-type LaCuOS single phase semiconducting and conducting thin films with record high conductivity of 136.7 S·cm^-1 and very good optical transparency of 80% at 600 nm and 40% at 5000nm. The optical gap is about 3.15 eV. The LaCuOS film can be semiconductor or conductor by controlling sulphuration. The optical transparency window of 400-6000 nm is amazingly wide, covering wavelengths from visible to middle infrared lights, indicating its potential applications in visible and infrared semiconductor devices and electronics. The Fermi level is very close to the valance band upper edge, suggesting that this material can be an excellent candidate of high work function transparent electrodes for photovoltaic and optoelectronic devices.