Optical anisotropy and spontaneous ordering in Ga[sub 0. 5]In[sub 0. 5]P: An investigation using reflectance-difference spectroscopy

Journal Article · Wed Mar 15 00:00:00 EST 1995 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.51.7603· OSTI ID:6457106

Luo, J S; Olson, J M; Kurtz, S R; Arent, D J; Bertness, K A ^[1]; Raikh, M E; Tsiper, E V ^[2]

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1. National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)
2. Department of Physics, University of Utah, Salt Lake City, Utah 84112 (United States)

We have applied reflectance-difference spectroscopy (RDS) to the study of optical anisotropy in spontaneously ordered Ga[sub 0.5]In[sub 0.5]P grown by metal-organic chemical-vapor deposition. The degree of order in Ga[sub 0.5]In[sub 0.5]P has been associated previously with a shift of the band-gap energy [Delta][ital E][sub 0] and a crystal-field valence-band splitting [Delta][sub [ital C]]. Theoretically, both quantities are, to first order, quadratic functions of the long-range order parameter [eta], which varies from 0 to 1 for disordered and perfectly ordered Ga[sub 0.5]In[sub 0.5]P, respectively. The main RD spectral feature in partially ordered Ga[sub 0.5]In[sub 0.5]P is a bulk-induced, asymmetric peak at [ital E][sub 0] with a long tail that extends well below [ital E][sub 0] and a sharp high-energy cutoff at [ital E][sub 0]+[Delta][sub [ital C]]. We find experimentally and theoretically that the intensity of this RD spectral feature is proportional to [radical]([Delta][ital E][sub 0]) and, therefore, is linear with the order parameter. This makes RDS particularly useful for measuring the optical anisotropy of high-band-gap Ga[sub 0.5]In[sub 0.5]P. We also compare heterostructures of GaAs and Al[sub 0.5]In[sub 0.5]P on Ga[sub 0.5]In[sub 0.5]P with uncoated Ga[sub 0.5]In[sub 0.5]P in an effort to separate bulk-, surface-, and interface-induced RD spectral features.

• OSTI ID: 6457106
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 51:12; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GALLIUM PHOSPHIDES
ORDER-DISORDER TRANSFORMATIONS
INDIUM PHOSPHIDES
CHEMICAL VAPOR DEPOSITION
OPTICAL REFLECTION
REFRACTIVE INDEX
SPECTRAL REFLECTANCE
CHEMICAL COATING
DEPOSITION
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
OPTICAL PROPERTIES
PHASE TRANSFORMATIONS
PHOSPHIDES
PHOSPHORUS COMPOUNDS
PHYSICAL PROPERTIES
PNICTIDES
REFLECTION
SURFACE COATING
360606* - Other Materials- Physical Properties- (1992-)