Electroluminescence of SnO2/p-Si heterojunction

Polycrystalline SnO2 film of tetragonal rutile structure with an optical band gap of 3.9 eV was formed by oxidation process at 1000 degrees C on electron beam evaporation deposited Sn film. Room temperature electroluminescence from the SnO2/p-Si heterojunction was observed at 590 nm when the device was under sufficient forward bias with the positive voltage applied on the p-Si substrate. It is proposed that the electrons in the conduction band of SnO2 relax to defect states that resulted from the dangling bonds at the surface of the small SnO2 grains and then radiatively recombine with the holes in the valence band. (c) 2008 American Institute of Physics.