Study of deep levels in InAlAsSb grown via organometallic vapor phase epitaxy

Abstract

Triple junction solar cells lattice matched to InP have the potential to exceed 50% efficiency under AM1.5 500x illumination with a bandgap stack of 1.74 11.1 10.7 eV. A top cell having 1.74 eV requires development of high-quality InAIAsSb, which currently has very little development effort reported. Preliminary deep-level transient spectroscopy results in p-type InAIAsSb indicate the presence of deep-levels 0.20 eV and 0.44 eV above the valence band with concentration _10 15 cm-3 • Experiments such as spectral response and dark IV analysis reveal poor solar cell metrics, which may be a direct consequence of the detected defects. The InAIAsSb deep-levels are comparedto the better-understood levels found in InAIAs, however, no evidence of a correlation is found.