Systematic optical and x-ray study of In x Ga1−x As on InP

Phonons inIn0.53Ga0.47As/IRowell1, Yu2, Lockwood3 et al. 2003Phys. Rev. B7000View full textAdd to dashboardCite

“…3,4 These techniques can also provide information on the atomic structure of the heterointerfaces and on confinement effects in very thin layers. 3,4 There have been many infrared [5][6][7][8][9][10][11][12][13][14][15][16][17][18] and Raman [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] investigations of the In 1Ϫx Ga x As alloy, principally in the form of strained ͑thin͒ or relaxed ͑thick͒ epilayers grown on GaAs or InP. However, there are wide differences among these investigations not only in the concentration dependence of the optical phonon frequencies but also in the number of modes observed and their origin ͑see, for example, Adachi 34 and Nash et al 35 ͒.…”

“…However, there are wide differences among these investigations not only in the concentration dependence of the optical phonon frequencies but also in the number of modes observed and their origin ͑see, for example, Adachi 34 and Nash et al 35 ͒. Most of the previous work has been about the optical phonons in bulk ͑i.e., unstrained͒ In 1Ϫx Ga x As as a function of x, whereas only relatively few studies 9,10,11,17,27,29,30 exist concerning phonons in the strained In 1Ϫx Ga x As/InP system. This latter group of investigations has revealed a nonlinear dependence on x of the frequencies of the GaAs-like and InAs-like longitudinal ͑LO͒ and transverse ͑TO͒ optical phonons ͑see, for example, Refs.…”

“…11 and 17͒, as well as a continuum of phonons between these two sets of modes that has been ascribed to disorder. 21,27 For the case of In 1Ϫx Ga x As/InP superlattices-the main interest of this paper-there has been no systematic study of the effects of strain and confinement by infrared and Raman spectroscopy. The latter method, however, has been used to probe phonons and their interaction with carriers in single In 1Ϫx Ga x As/InP quantum wells; [36][37][38][39][40][41] folded acoustic, layer, and interface modes in In 0.53 Ga 0.47 As/InP superlattices; 42,43 and strain in InAs/InP single wells 44 and superlattices.…”