Combining photoluminescence and photocurrent measurements to distinguish photovoltaic losses

We measure the photoluminescence and photocurrent of a blue LED under open- and short-circuit conditions to distinguish between drift and non-drift related carrier loss mechanisms. We also vary the excitation intensity and temperature to monitor changes in recombination parameters. Using a simple rate equation model, we find that diffusion-related non-radiative recombination is thermally activated with an activation energy equal to approximately 44 meV, while drift-related losses account for an excitation- and temperature-independent 10% short-circuit current deficit when the carrier density exceeds a threshold of 5 × 10 14 cm −3 .