Reflected-light, photoluminescence and OBIC imaging of solar cells using a confocal scanning laser MACROscope/microscope

This paper describes a confocal scanning beam MACROscope/Microscope which can image specimens up to 7x7 cm in size using reflected light, photoluminescence and optical beam induced current. The MACROscope provides a 10 mu m spot size at various wavelengths and generates 512 x 512 pixel images in less than 5 s. When used in combination with a conventional confocal scanning laser microscope sub-micron spot sizes become possible providing resolutions as high as 0.25 mu m laterally and 0.5 mu m axially in reflected light. The main function of this imaging system is to spatially resolve any defects within solar cells and similar devices. Several reflected-light, photoluminescence and OBIC images of CdS/CuInSe2 and CdZnS/CuInSe2 thin film solar cells are presented.