Electroluminescence from Au native silicon oxide layer p+-Si and Au native silicon oxide layer n+-Si structures under reverse biases

Electroluminescence (EL) from an Au/native silicon oxide layer (NSOL)/p(+)-Si structure and an Au/NSOL/n(+)-Si structure has been observed and their EL characteristics have been studied comparatively with those from an Au/NSOL/p-Si structure. The Au/NSOL/p-Si structure emits red light only when a forward bias larger than 3 V is applied, while no light emission can be observed under reverse biases. However, the Au/NSOL/p(+)-Si structure or the Au/NSOL/n(+)-Si structure emits red light when the applied reverse bias is greater than a critical value around 3 V, while no light emission can be observed under forward biases. It is suggested that for EL from the Au/NSOL/p(+)-Si and Au/NSOL/n(+)-Si structures under reverse biases, electrons and holes which are generated in the NSOLs by impact ionization in breakdown states radiatively recombine via the luminescence centres in the NSOL to emit light.