Residual acceptor impurities in undoped high-purity InP grown by metalorganic chemical vapor deposition

Abstract

Zn and an unidentified acceptor species, labeled A1, are the only residual acceptors that have been observed in a wide variety of undoped high-purity InP samples grown by metalorganic chemical vapor deposition. Carbon is not incorporated at detectable concentrations as a residual acceptor in metalorganic chemical vapor deposited InP. However, the longitudinal and transverse optical phonon replicas of the free-exciton recombination occur at the same energy as the donor/conduction band-to-acceptor peaks for C acceptors in low-temperature photoluminescence spectra. Since these replicas are usually present in photoluminescence spectra measured under moderate or high optical excitation, care must be exercised so that these peaks are not misinterpreted as C-related transitions.

Piezoreflectance study of InP near the absorption edge

“…They observed an acceptor-related line situated about 40 meV below the fundamental absorption edge. The acceptor responsible for the 1.38 eV line is assigned to be Zn which is a dominant acceptor for InP single crystals [21,22]. Feature A 1 disappears at lower temperature.…”