Compressed sensing current mapping spatial characterization of photovoltaic devices

A new photovoltaic (PV) device current mapping method has been developed, combining the recently introduced Compressed Sensing (CS) sampling theory with Light Beam Induced Current (LBIC) measurements. Instead of a raster scan, compressive sampling is applied using a Digital Micro-mirror Device (DMD). The aim is to significantly reduce the time required to produce a current map, compared to conventional LBIC measurements. This is achieved by acquiring fewer measurements than a full raster scan and by utilizing the fast response of the micro-mirror device to modulate measurement conditions. The method has been implemented on an optical current mapping setup built at the National Physical Laboratory (NPL) in the UK. Measurements with two different PV cells are presented in this work and an analytical description for realisation of an optimised CS current mapping system is provided. The experimental results illustrate the feasibility of the method and its potential to significantly reduce measurement time of current mapping of PV devices.