Improved local efficiency imaging via photoluminescence for silicon solar cells

•A method to produce an improved efficiency image of solar cell via PL.•Some other parameters images are produced simultaneously.•This method is spatially resolved, fast, non-destructive and accurate.•The result maps have good agreement with DLIT measurements.•After many tests on samples, it seems to be reliable and reproducible.

We present an improved method that uses photoluminescence images to calculate the spatially-resolved efficiency in addition to other performance parameters of silicon solar cells. This new method is simpler than our previously-presented two-diode method, using only one diode with a variable ideality factor. Experimental results show that the simplified method is more tolerant of very large variations in local series resistance, a characteristic commonly seen in silicon cells. Using dark lock-in thermography techniques, we quantitatively verify the efficiency images produced by our improved method.