Band profiling of p-Si/ITO interface by Kelvin probe force microscopy under light controlled conditions

Abstract

Kelvin probe force microscopy (KFM) measurements have been performed on cleaved p-Si/ITO (indium tin oxide) interfaces under light controlled conditions. The contact potential difference (CPD) measured by KFM are converted into work function, and hence the band alignment of the interfaces are obtained. We observe that the average work function differences between the p-Si and ITO layers are reduced from that in dark when illuminated.We tentatively attribute this result to the increase in the photogenerated hole density upon illumination, smoothing and widening the band bending in the ITO layer as well.