Photoacoustic Signals of Depletion Layer Spread Beneath Metal Electrode in Metal/Semiconductor Structure

Abstract

SUMMARYThe photoacoustic (PA) signal from the depletion layer beneath the metal electrode in a metal/semiconductor (M/S) structure was detected using the PA method. To measure the reverse-bias voltage dependence of distribution of the PA signal from the depletion layer, the surface of the electrode was illuminated and scanned by an intensitymodulated optical beam. It was found that the PA signal phase differences between depletion layer formation and the absence of a depletion layer were dependent on depletion layer spreading. One-dimensional scanning of the electrode also revealed that spreading of the depletion layer extends from the edges of the electrode. C⃝