CuBO2: a p-type transparent oxide

The authors report the synthesis of CuBO2, a p-type transparent oxide belonging to Cu-delafossite family. High quality thin films of CuBO2 were deposited on c-plane sapphire substrates by pulsed laser deposition technique. Detailed structural, optical, and electrical characterizations on these films were performed. Optical transmission measurement showed the films to be highly transparent in the visible range and having indirect and direct band gaps of 2.2 and 4.5 eV, respectively. Room-temperature electrical conductivity of CuBO2 films was 1.65 S cm−1 and exhibited semiconductorlike temperature dependence. The Hall and Seebeck coefficients of the film were positive, indicating the p-type nature of the material.