Effects of stoichiometry on electrical, optical, and structural properties of indium nitride

Journal Article · Tue Nov 01 00:00:00 EST 2005 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2130514· OSTI ID:20719662

Ho, J C; Specht, P; Yang, Q; Xu, X; Hao, D; Weber, E R ^[1]

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1. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 and Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States)

A series of indium nitride (InN) epilayers with different excess indium (In) concentration are grown by plasma-assisted molecular-beam epitaxy on (0001) sapphire substrates. The increasing excess In concentration of the epilayers correlates with an increasing free-electron concentration and a decreasing electron mobility. Photoluminescence (PL) illustrates a 0.77-0.84 eV transition for all samples with a redshift in the peak energy with increasing In concentration (for the highest free-electron concentration of 4x10{sup 21} cm{sup -3}). This suggests that the {approx}0.8 eV PL transition is not consistent with the band-edge transition in InN. Moreover, an additional PL transition at 0.75 eV along with the In clusters observed in transmission electron microscopy analysis are found only in the 29% excess In sample. This implies a relationship between the new PL transition and the presence of In clusters. Finally, secondary-ion mass spectrometry is used to verify that the contamination, especially hydrogen (H) and oxygen (O) impurities, has no influence on the redshift of the {approx}0.8 eV PL peaks and the existence of the additional 0.75 eV peak in the sample containing In clusters.

• OSTI ID: 20719662
• Journal Information: Journal of Applied Physics, Vol. 98, Issue 9; Other Information: DOI: 10.1063/1.2130514; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARRIER DENSITY
CHEMICAL VAPOR DEPOSITION
CRYSTAL GROWTH
ELECTRON MOBILITY
IMPURITIES
INDIUM NITRIDES
ION MICROPROBE ANALYSIS
LAYERS
MASS SPECTROSCOPY
MILLI EV RANGE
MOLECULAR BEAM EPITAXY
PHOTOLUMINESCENCE
PLASMA
RED SHIFT
SAPPHIRE
SEMICONDUCTOR MATERIALS
STOICHIOMETRY
SUBSTRATES
TRANSMISSION ELECTRON MICROSCOPY