Correlations between electrical and optical properties in lattice-matched GaAsPN/GaP solar cells

In this work, we investigate correlations between optical and electro-optical properties of GaAsPN/GaP p-i-n solar cells grown by MBE on GaP(001) substrates. A photoluminescence model is first proposed to extract the long range compositional fluctuation energy scale from low temperature photoluminescence spectra of the GaAsPN dilute-nitride material. Solar cells grown with the same nitrogen content at different temperature reveal very different electrical performances. A 4.08 mA/cm2 short-circuit current density has been obtained, that is an excellent value given the small absorber thickness (300 nm) and high material bandgap. Comparisons between solar cells photoluminescence, I-V (under AM1.5G illumination) and IQE parameters reveal correlations between their optical and electrical parameters. These results reinforce PL measurements interest for dilute nitride solar cells growth optimization.