Dilute III-PBi and III-SbBi for IR applications

Paper in proceeding, 2016

In this paper, I present recent progresses on epitaxial growth and material characterizations of novel dilute III-PBi and III-SbBi. High quality dilute bismide thin films can be epitaxially grown by molecular beam epitaxy in a narrow growth parameter window. Up to 13% and 4.3% Bi is incorporated in GaSbBi and InPBi, respectively, and majority Bi atoms are at the lattice position as confirmed by Rutherford backscattering spectroscopy. For the quaternary InGaPBi and InAlPBi, the strain can be tuned from tensile to compressive by increasing Bi concentration. The thin films also reveal strong and broad photoluminescence up to 2.7 mu m and large band-gap reduction. Structural and chemical analysis indicates a non-uniform distribution of Bi, and various Bi related defects are directly imaged in scanning tunneling microscopy. Such defects are the origins for deep levels confirmed by deep level transient spectroscopy and have profound effect on photoluminescence spectra.