Screen-display-induced photoresponse mapping for large-area photovoltaics

Abstract

As solar cell modules are becoming larger, it is important to pay attention to defects originating from the fabrication process and degradation during operation in the ambient. In this article, a simple method of using computer screen display as a light source to map the photoresponse of the solar cells, is reported. The method requires only a conventional computer loaded with a software code that enables a light spot of defined size to raster scan across the cell area as the photogenerated voltage is read out by a voltmeter using a USB connection. Screen-display-induced photoresponse (SDIP) mapping is an enabling technique to reveal the defective regions in the active layer as well as at the electrode interface, which, in many instances, cannot be deciphered simply by visual examination. Spectral response mapping by using light spots of different colors is also possible.