Control of hole carrier density of polycrystalline Cu2O thin films by Si doping

The effects on the electrical properties of Si doping into ${\mathrm{Cu}}_2\mathrm{O}$ thin films deposited by reactive sputtering were studied. The hole density increased from ${\text{1×10}}^{15}$ to ${\text{1×10}}^{17}\hspace{0.17em}{\mathrm{cm}}^{\text{−3}}$ with increasing Si content and the minimum resistivity obtained was 12 Ω cm. It was suggested that the electrically active acceptor with an activation energy of 0.19 eV was generated by Si doping. Infrared absorption measurements indicated the formation of silicate in Si-doped ${\mathrm{Cu}}_2\mathrm{O}.$ The mechanism for Si acting as an acceptor in ${\mathrm{Cu}}_2\mathrm{O}$ is discussed and modeled based on the silicate formation in ${\mathrm{Cu}}_2\mathrm{O}.$