The photoelastic coefficient P12 of H+ implanted GaAs as a function of defect density

• Published in: Scientific reports Vol. 7; no. 1; p. 15150
• Main Authors: Baydin, Andrey, Krzyzanowska, Halina, Gatamov, Rustam, Garnett, Joy, Tolk, Norman
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09.11.2017
• Subjects: 140/125; 639/766/119/1000; 639/766/400/584; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-14903-x

The photoelastic phenomenon has been widely investigated as a fundamental elastooptical property of solids. This effect has been applied extensively to study stress distribution in lattice-mismatched semiconductor heterostructures. GaAs based optoelectronic devices (e.g. solar cells, modulators, detectors, and diodes) used in space probes are subject to damage arising from energetic proton (H + ) irradiation. For that reason, the effect of proton irradiation on photoelastic coefficients of GaAs is of primary importance to space applied optoelectronics. However, there yet remains a lack of systematic studies of energetic proton induced changes in the photoelastic properties of bulk GaAs. In this work, the H + energy and fluence chosen for GaAs implantation are similar to that of protons originating from the radiation belts and solar flares. We present the depth-dependent photoelastic coefficient P 12 profile in non-annealed H + implanted GaAs obtained from the analysis of the time-domain Brillouin scattering spectra. The depth-dependent profiles are found to be broader than the defect distribution profiles predicted by Monte Carlo simulations. This fact indicates that the changes in photoelastic coefficient P 12 depend nonlinearly on the defect concentrations created by the hydrogen implantation. These studies provide insight into the spatial extent to which defects influence photoelastic properties of GaAs.