Optical activation of Si nanowires by Er3+ doped binary Si–Al oxides films derived from sol–gel solutions

The optical activation of Si nanowires (SiNWs) by the coating of Er3+ doped binary silicon–aluminum oxides (Si–Al oxides) films derived from sol–gel solutions is reported. Continuous and crack-free Si–Al oxide film could be successfully coated onto an Si substrate where the SiNWs were grown. The strong Er3+ luminescence of 1.534 μm from the SiNWs was observed at a high Er concentration (5 at.%). These results suggest that the Al–Si oxide film makes it possible to realize a strong Er3+ luminescence by excluding concentration quenching while at the same time improving the quality of film.