Fabrication and optical properties of silicon nanowire/Cu2O nano-heterojunctions by electroless deposition technique

Si NWs/Cu2O nano-heterojunctions were prepared by adopting electroless deposition technique to deposit Cu2O nanocrystallines on the surface of silicon nanowire arrays (Si NWs). Raman spectra of the composite structures demonstrate that the infrared (IR) active mode originated from the defects in the crystal lattice and is activated in Cu2O nanocrystallines. Photoluminescence (PL) spectra of the nano-heterojunctions suggest that the as-prepared Si NWs/Cu2O composite structures present a new luminescence wavelength after the formation of nano-heterojunctions. In addition, the PL peak of Si NWs in the composite structure exhibits a little red-shift and becomes broad in comparison with that of the pure Si NWs. The radial Si NWs/Cu2O nano-heterojunction structure would have promising applications in many fields such as heterojuncion solar cell, photocatalysis, and water splitting hydrogen generation.