Visible electroluminescence from porous silicon

Abstract

It is demonstrated that photoluminescent porous Si (PS) layers exhibit definitely visible electroluminescence (EL). The PS layers were formed by anodization of single‐crystal nondegenerate p‐type Si wafers in an HF solution. The experimental EL cells are of the form semitransparent metal/PS layer/p‐type Si/Al electrode. These cells show a rectifying junction behavior. When the forward current density reaches a certain value, stable visible (orange) light is uniformly emitted through a semitransparent electrode. A possible explanation of this is the radiative transition due to electron and hole injection into quantized states in PS.