Correlation Between Measured Minority-Carrier Lifetime and Cu(In, Ga)Se2 Device Performance

The relationship between lifetime measured by time-resolved photoluminescence on bare Cu(In, Ga)Se-2 films and subsequent device performance is examined. Devices and films from both the laboratory and a 40-MW manufacturing line are examined. A correlation between the device voltage and lifetime is demonstrated. The effects of the measured band gap and carrier density are discussed. A method to account for the effects of varying band-gap and carrier density profiles, without requiring computer modeling, is presented. Results are compared with fundamental calculations.