Acoustical and optical properties of Ga0.52In0.48P: A Brillouin scattering study

Abstract

Brillouin scattering is used to determine the refractive index N=n+iκ of Ga0.52In0.48P layers, lattice matched to GaAs, in a wavelength range never investigated before (400 nm<λ<800 nm). It is shown that the variations of n are given by two different analytical expressions, depending on whether the corresponding photon energies E are lower or higher than the band gap Eg. Optical absorption measurements are deduced from the Brillouin linewidth. The whole set of elastic constant is also determined through the Brillouin shifts. For E∼Eg, i.e., in resonance conditions, n displays a small but sharp peak closely related to the abrupt increase of the optical absorption. Besides the Brillouin investigations, complementary results obtained by ellipsometry and Raman spectroscopy confirm our optical properties measurements in Ga0.52In0.48P and the electronic resonance behavior, respectively.

Optical Properties

“…Brillouin scattering has been used to determine the complex refractive indices n à (E) in the region below the fundamental absorption edge of Ga 0.52 In 0.48 P latticematched to GaAs [62]. The optical absorption and hydrostatic-pressure effect at the fundamental absorption edge of Ga x In 1Àx P (0.36 x 0.5) have also been measured by Goñi et al [63].…”

A Brillouin light scattering study of the elastic properties of superlattices grown by chemical beam epitaxy

“…In some specific cases, 0953-8984/96/142265+08$19.50 c 1996 IOP Publishing Ltd this procedure has been used for determining the whole set of elastic constants, but this led to rather large errors, especially regarding the value of the elastic constant c 12 [6]. Very recently, Krieger et al used near-infrared Brillouin scattering from bulk waves for determining the elastic constants of the AlGaAs system [7], while Hassine et al investigated the acoustic and optical properties of GaInP films with a wide band gap, by studying the scattering of light with different wavelengths from bulk acoustic phonons [8].…”