The molecular beam epitaxial growth of GaPSb and Ga-rich AlGaPSb nearly lattice matched to InP has been investigated. The effect of growth temperature, P flux, Ga flux, and Sb flux on the alloy P/Sb ratio was examined. The 300 K band gap of lattice-matched GaPSb was estimated to be 0.84 eV based on photoluminescence measurements, and the shift of band gap energy with Al content in AlGaPSb alloys with Al fractions of 0.03-0.04 was investigated. A conduction band offset of approximately 0.15 eV in a type-II configuration was estimated between lattice-matched Al0.04Ga0.96P0.35Sb0.65 and InP based on photoluminescence characterization of multiple quantum well structures. AlGaPSb/InP distributed Bragg reflectors (DBRs) with a stopband centered on 1550 nm were grown with excellent lattice matching and good surface morphology. A refractive index difference of 0.41 between these materials was estimated based on a fit to the DBR reflectance spectrum. (C) 2004 American Vacuum Society.