Electroluminescence from semitransparent Au film/nanometer SiO₂/nanometer Si/nanometer SiO₂/n⁺-Si structure under reverse bias

Nanometer SiO₂/nanometer Si/nanometer SiO₂ double-barrier (DB) structures, with Si layers having eleven different thicknesses from 2 to 4 nm, were deposited on n⁺-Si substrates using the magnetron sputtering technique. Strong electroluminescence (EL) from semitransparent Au film/DB/n⁺-Si structure was observed under reverse bias in a range of about 5-7 V. It is found that every EL spectrum of the structure can be decomposed into two Gaussian bands with peaks at around 1.85 and 2.25 eV, and their intensities and current swing synchronously with increasing nanometer Si layer thickness; the periodic length of swing is consistent with half of the de Broglie wavelength of the carriers. A comparison was carried out between EL from the Au/DB/n⁺-Si structure under reverse bias and that from the Au/DB/p-Si structure under forward bias reported previously.