Nature of the fundamental band gap in GaN{sub x}P{sub 1-x} alloys

Journal Article · Mon May 29 04:00:00 EDT 2000 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.126597· OSTI ID:20216502

Shan, W ^[1]; Walukiewicz, W ^[1]; Yu, K M ^[1]; Wu, J ^[1]; Ager, III, J W ^[1]; Haller, E E ^[2]; Xin, H P ^[3]; Tu, C W ^[3]

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1. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
2. Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California (United States)
3. Department of Electrical and Computer Engineering, University of California at San Diego, La Jolla, California 92093 (United States)

The optical properties of GaN{sub x}P{sub 1-x} alloys (0.007{<=}x{<=}0.031) grown by gas-source molecular-beam epitaxy have been studied. An absorption edge appears in GaN{sub x}P{sub 1-x} at energy below the indirect {gamma}{sub V}-X{sub C} transition in GaP, and the absorption edge shifts to lower energy with increasing N concentration. Strong photomodulation signals associated with the absorption edges in GaN{sub x}P{sub 1-x} indicate that a direct fundamental optical transition is taking place, revealing that the fundamental band gap has changed from indirect to direct. This N-induced transformation from indirect to direct band gap is explained in terms of an interaction between the highly localized nitrogen states and the extended states at the {gamma} conduction-band minimum. (c) 2000 American Institute of Physics.

• OSTI ID: 20216502
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 22 Vol. 76; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTRA
DOPED MATERIALS
ENERGY GAP
ENERGY-LEVEL TRANSITIONS
EXPERIMENTAL DATA
GALLIUM PHOSPHIDES
MOLECULAR BEAM EPITAXY
NITROGEN ADDITIONS
PHOTOLUMINESCENCE