Thin film growth of the p-type semiconductor BiCuOSe by pulsed laser deposition*

Thin films of p-type semiconductor BiCuOSe were prepared by pulsed laser deposition onto fused SiO$_{2}$ and single crystal MgO and SrTiO$_{3}$ substrates. Their electrical and optical properties were measured. Ca-doped films prepared on MgO or SrTiO$_{3}$ substrates are $c$-axis oriented, and show high electrical conductivity of $\sim $200 S/cm and high reflectivity of 30-50{\%} from $\sim $0.4-4 $\mu$m. Single phase polycrystalline films on fused SiO2 show lower conductivity of $\sim $9 S/cm and reveal a weak transmission turn on near 950 nm (1.3 eV) indicative of the band gap absorption. BiCuOSe is isostructural with the transparent p-type conductor LaCuOSe, but forms at much lower temperatures. Possible applications include use as a solar cell absorber.