SrCu 2 O 2 : A p-type conductive oxide with wide band gap

Abstract

${\mathrm{SrCu}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{2}}$ thin films were prepared on ${\mathrm{SiO}}_{\mathrm{2}}$ glass substrates by pulsed laser deposition. The film deposited in ${\mathrm{O}}_{\mathrm{2}}$ atmosphere of ${\text{7×10}}^{\text{−4}}\hspace{0.17em}\mathrm{Pa}$ at 573 K showed high optical transmission in visible and near-infrared regions. Potassium was doped at Sr site for substitutional doping. The optical band gap of the K-doped film was estimated to be ∼3.3 eV. The dc electrical conductivity of the K-doped film at 300 K was ${\text{4.8×10}}^{\text{−2}}\hspace{0.17em}{\mathrm{S\hspace{0.17em}cm}}^{\mathrm{-1}}$ and the activation energy was 0.10 eV. Positive sign of Seebeck and Hall coefficients demonstrated the p-type conduction of the film. Hole concentration and mobility at 300 K were ${\text{6.1×10}}^{17}\hspace{0.17em}{\mathrm{cm}}^{\mathrm{-3}}$ and $\text{0.46\hspace{0.17em}}{\mathrm{cm}}^{\mathrm{2}}{\mathrm{\hspace{0.17em}V}}^{\mathrm{-1}}{\mathrm{\hspace{0.17em}s}}^{\mathrm{-1}},$ respectively.