The Dynamic Ultrasound Influence on the Diffusion and Drift of the Charge Carriers in Silicon p-n Structures

Abstract

Study of the current-voltage (I-V) characteristics of silicon solar cells, treated by MHz ultrasound with intensity up to 3 W/cm 2 have been carried out. It is revealed that under such nonequilibrium conditions, the minority carriers' diffusion process changes, which leads to the increase of the photocurrent (up to 15 %). An acoustostimulated reduction (down to 40 %) of the saturation current of the p-n junction is also observed. It is determined, that the observed changes depend nonlinearly on ultrasound power density, and the efficiency of the ultrasound influence increases with the vibration frequency. We consider that the ultrasound induced effects are connected with nonequilibrium processes of ionization and reorientation of structural defects in the acoustic field.