Observation of quasidirect transitions in In[sub 1[minus][ital x]]Ga[sub [ital x]]P/graded GaP (0. 58[le][ital x][le]0. 75) alloys near the [Gamma]-[ital X][sub 1] crossover
- Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (United States) Department 1112, MS 0350, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
- Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (United States)
- Department of Physics, Emory University, Atlanta, Georgia 30322 (United States)
- Department 1322, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States)
- Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois 61801 (United States)
- Department of Material Science, University of Cincinnati, Ci
We used room-temperature ellipsometry to study the quasidirect (no-phonon) transitions of [ital disordered] In[sub 1[minus][ital x]]Ga[sub [ital x]]P/graded GaP near crossover compositions (0.64[le][ital x][le]0.75) for the [Gamma][sub 1[ital c]] and [ital X][sub 1[ital c]] conduction-band minima. Careful study of sample microstructures by transmission electron microscopy revealed no ordering. We identify the observed transitions at ([Gamma][sub 15[ital v]-][ital X][sub 1[ital c]]), ([Gamma][sub 15[ital v]-][ital L][sub 1[ital c]]), and ([Gamma][sub 15[ital v]-][ital X][sub 3[ital c]]). The enhanced amplitude of the quasidirect transitions is attributed to band mixing between [Gamma] and [ital L] or [ital X] points in [ital k] space. This observation is corroborated by low-temperature photoluminescence and time-decay experiments. A two-level anticrossing behavior of the [Gamma][sub 1[ital c]] and [ital X][sub 1[ital c]] gaps is observed in photoluminescence with [Gamma]-[ital X] mixing energy [vert bar][ital V][sub [Gamma]-[ital X]][vert bar][approx]12 meV induced by random-alloy disorder.
- DOE Contract Number:
- AC04-94AL85000; FG02-91ER45439
- OSTI ID:
- 6585109
- Journal Information:
- Physical Review, B: Condensed Matter; (United States), Vol. 51:7; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GALLIUM PHOSPHIDES
ENERGY-LEVEL TRANSITIONS
INDIUM PHOSPHIDES
AMBIENT TEMPERATURE
ELLIPSOMETRY
MICROSTRUCTURE
PHOTOLUMINESCENCE
TERNARY ALLOY SYSTEMS
ALLOY SYSTEMS
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
LUMINESCENCE
MEASURING METHODS
PHOSPHIDES
PHOSPHORUS COMPOUNDS
PNICTIDES
360606* - Other Materials- Physical Properties- (1992-)