Strong blue and violet photoluminescence and electroluminescence from germanium-implanted and silicon-implanted silicon-dioxide layers

The photoluminescence (PL) and electroluminescence (EL) properties of Ge-implanted ${\mathrm{SiO}}_{\mathrm{2}}$ layers thermally grown on a Si substrate were investigated and compared to those of Si-implanted ${\mathrm{SiO}}_{\mathrm{2}}$ films. The PL spectra from Ge-implanted ${\mathrm{SiO}}_{\mathrm{2}}$ were recorded as a function of annealing temperature. It was found that the blue-violet PL from Ge-rich oxide layers reaches a maximum after annealing at 500 °C for 30 min, and is substantially more intense than the PL emission from Si-implanted oxides. The neutral oxygen vacancy is believed to be responsible for the observed luminescence. The EL spectrum from the Ge-implanted oxide after annealing at 1000 °C correlates very well with the PL one, and shows a linear dependence on the injected current. The EL emission was strong enough to be readily seen with the naked eye and the EL efficiency was assessed to be about ${\text{5×10}}^{\text{−4}}.$