Investigation of E{sub 1}(LO) phonon-plasmon coupled modes and critical points in In{sub 1-x}Ga{sub x}N thin films by optical reflectance measurements

Journal Article · Mon May 03 04:00:00 EDT 2010 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3428368· OSTI ID:21347416

Thakur, J S; Dixit, A; Sudakar, C; Naik, R ^[1]; Danylyuk, Y V ^[2]; Naik, V M ^[3]; Schaff, W J ^[4]

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1. Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48202 (United States)
2. Department of Electrical and Computer Engineering, Wayne State University, Detroit, Michigan 48202 (United States)
3. Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan 48128 (United States)
4. Department of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14583 (United States)

Low energy optical modes of molecular beam epitaxy-grown In{sub 1-x}Ga{sub x}N thin films with 0<=x<=0.6 are investigated using infrared reflectance measurements. We found that the reflectance of the films for wave vectors in the range from 600 to 800 cm{sup -1} is determined by the high energy E{sub 1}(LO)-plasmon coupled modes. In the higher energy regime of the UV-visible reflectance spectrum of InN, critical points with energies 4.75, 5.36, and 6.12 eV belonging to A and B structures are observed. The energies of these critical points increase with increasing values of x, similar to the band gap energy of these films.

• OSTI ID: 21347416
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 18 Vol. 96; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL GROWTH
CRYSTAL GROWTH METHODS
ENERGY GAP
ENERGY RANGE
EPITAXY
EV RANGE
EV RANGE 01-10
FILMS
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
INDIUM NITRIDES
INFRARED SPECTRA
MATERIALS
MOLECULAR BEAM EPITAXY
NITRIDES
NITROGEN COMPOUNDS
OPTICAL MODES
OSCILLATION MODES
PHONONS
PNICTIDES
QUASI PARTICLES
SEMICONDUCTOR MATERIALS
SPECTRA
TENSORS
THIN FILMS
ULTRAVIOLET SPECTRA
VECTORS
VISIBLE SPECTRA