Narrow band gap (1eV) InGaAsSbN solar cells grown by metalorganic vapor phase epitaxy

Heterojunction solar cell structures employing InGaAsSbN (Eg ∼ 1eV) base regions are grown lattice-matched to GaAs substrates using metalorganic vapor phase epitaxy. Room temperature (RT) photoluminescence (PL) measurements indicate a peak spectral emission at 1.04eV and carrier lifetimes of 471-576 ps are measured at RT from these structures using time-resolved PL techniques. Fabricated devices without anti-reflection coating demonstrate a peak efficiency of 4.58% under AM1.5 direct illumination. Solar cells with a 250nm-thick InGaAsSbN base layer exhibit a 17% improvement in open circuit voltage (V oc ), 14% improvement in fill factor, and 12% improvement in efficiency over the cells with a thicker (500nm-thick) base layer.