Photoluminescence Imaging and Characterization of Single and Multi-Junction Solar Cells

A method is proposed for large area, highly uniform photoluminescence imaging of single and multi-junction solar cells and solar cell arrays. Relative photoluminescence across a large area can be rapidly determined due to highly uniform excitation illumination and minimal measurement artifacts. Varying the wavelength of the excitation illumination enables the measurement of the photoluminescence of a variety of solar cell materials and of multiple sub-cells in a multi-junction device. This method allows for rapid characterization of spatially resolved device parameters. Thereby providing insight to the condition of solar cells including the nature of potential degradation that would not be readily conveyed via overall performance measurements using techniques that can be performed while the array is installed into a functional end use system.