Anodic dissolution and electroluminescence of p-Si at high potentials in fluoride media

The electrochemical dissolution of silicon in fluoride media under very high potentials (5-100 V) was investigated. The interface was characterized by voltammetry and in situ infrared spectroscopy. The infrared results indicate that the interracial oxide becomes porous above a critical potential of ∼20 V. Light emission from the interface was observed for potentials above ∼10 V. The electroluminescence signal was found to be composed of a red component and a blue component. Both components exhibit an increase in intensity as a function of applied potential, but their distinct dependence suggests that they arise from two distinct types of oxide detects and excitation mechanisms.