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Title: Study of strain and disorder of In[sub [ital x]]Ga[sub 1[minus][ital x]]P/(GaAs, graded GaP) (0. 25[le][ital x][le]0. 8) using spectroscopic ellipsometry and Raman spectroscopy

Journal Article · · Journal of Applied Physics; (United States)
DOI:https://doi.org/10.1063/1.355746· OSTI ID:7072396
 [1];  [2];  [3];  [2];  [4];  [5];  [6];  [7]
  1. Department of Physics, 1110 W. Green Street, and Materials Research Laboratory, 104 S. Goodwin Avenue, University of Illinois Urbana, Illinois 61801 (United States)
  2. Materials Research Laboratory, 104 S. Goodwin Avenue, Urbana, Illinois 61801 (United States)
  3. Department of Physics, 1110 W. Green Street, and Materials Research Laboratory, 104 S. Goodwin Avenue, Urbana, Illinois 61801 (United States)
  4. Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States)
  5. Department of Physics, Seoul National University, Shinlim-dong, Kwanak-ku, Seoul (Korea, Republic of)
  6. Department of Material Science and Engineering, 1304 W. Green Street, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)
  7. Department of Physics, 1110 W.

The optical properties of In[sub [ital x]]Ga[sub 1[minus][ital x]]P/GaAs and In[sub [ital x]]Ga[sub 1[minus][ital x]]P/graded InGaP/GaP (0.25[le][ital x][le]0.8) epitaxial layers have been studied using spectroscopic ellipsometry and Raman spectroscopy. The ([ital E][sub 1],[ital E][sub 1]+[Delta][sub 1]) critical points and the first-order phonon frequencies were determined as a function of In composition. The general behavior of the peak shifts and broadenings of both the [ital E][sub 1] gaps and the optical phonons of In[sub [ital x]]Ga[sub 1[minus][ital x]]P/GaAs can be explained in terms of biaxial strain and strain relaxation caused by lattice-mismatch. The near-cancellation of [ital E][sub 1] gap change due to the compensation effect between alloy composition and misfit strain is observed. As misfit strain increases, the [ital E][sub 1] gap broadens whereas the phonon line shape does not change. In strain relaxed samples of In[sub [ital x]]Ga[sub 1[minus][ital x]]P/(GaAs, graded GaP) (0.3[le][ital x][le]0.8), the [ital E][sub 1] gap linewidth shows upward bowing as a function of In composition.

DOE Contract Number:
AC02-76ER01198; FG02-91ER45439
OSTI ID:
7072396
Journal Information:
Journal of Applied Physics; (United States), Vol. 75:10; ISSN 0021-8979
Country of Publication:
United States
Language:
English