Correlation of Electroluminescence With Open-Circuit Voltage From Thin-Film CdTe Solar Cells

Electroluminescence (EL) measurements of several CdTe solar cells, a GaAs solar cell, and an AlGaAs LED were performed. The mean integrated EL intensity, normalized to exposure time and injection-current density, correlates well with the difference between ideal open-circuit voltage and measured open-circuit voltage, nearly independently of cell details or uniformity. This trend holds for devices of different absorber materials but does not hold for devices which exhibit poor superposition between light and dark current-voltage (J-V) curves.