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.