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Title: Spontaneous lateral phase separation of AlInP during thin film growth and its effect on luminescence

The occurrence of spontaneous lateral phase separation during thin film growth of Al{sub x}In{sub 1−x}P by metal-organic chemical vapor deposition was investigated using a combination of transmission electron microscopy and atom probe tomography to obtain a quantitative view of this phenomenon. An anisotropic and coherent composition modulation was observed in the nearly lattice-matched films deposited below 750 °C with a quasi-linear amplification with thickness that was inversely proportional to the growth temperature. The periodicity of the modulation increased exponentially with the growth temperature. A comparison of photoluminescence from phase separated and homogenous direct band gap Al{sub x}In{sub 1−x}P deposited on metamorphic In{sub y}Ga{sub 1−y}As graded buffers showed a lowering of peak-emission energy in accordance with the atom probe compositional characterization without any degradation in luminous intensity. Additionally, indications of carrier trapping in the low band gap regions were observed even at room-temperature. While some of these results are in qualitative agreement with theoretical models of kinetic instability in unstrained alloy growth in the literature, significant discrepancies remain.
Authors:
;  [1] ;  [2] ; ;  [3]
  1. Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
  2. National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)
  3. Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
Publication Date:
OSTI Identifier:
22489512
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 11; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CARRIERS; CHEMICAL VAPOR DEPOSITION; INSTABILITY; ORGANOMETALLIC COMPOUNDS; PEAKS; PHOTOLUMINESCENCE; PROBES; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; TRAPPING