Deposition and characterization of lithium doped direct current magnetron sputtered C u 2 O films

Highlights: • Preparation of Li doped Cu2O films by reactive magnetron sputtering. • High optical transmittance and phase purity in highly doped films. • High acceptor density correlated with high Li doping concentrations. Lithium doped cuprous oxide ($C{u}_{2}O:Li$) films were deposited on quartz substrates by direct current magnetron reactive co-sputtering of copper and $Cu:Li$ targets. X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), Rutherford backscattering spectrometry, UV-VIS transmittance, and room temperature Hall measurements have been conducted to characterize the deposited films. SIMS revealed Li concentrations in the range $2\times {10}^{18}-5\times {10}^{20}c{m}^{-3}$ in the doped films. XRD confirms phase pure $C{u}_{2}O$ for all doping concentrations. The doping concentration correlates with an increased free carrier density found from Hall effect measurements. The highest Li doping concentration results in low resistivity ($4\Omega cm$) p-type $C{u}_{2}O$ with acceptor concentrations up to $2\times {10}^{17}c{m}^{-3}$.