Exciton localization in AlGaN alloys

N. Nepal; J. Li; M. L. Nakarmi; J. Y. Lin; H. X. Jiang

doi:10.1063/1.2172728

Exciton localization in AlGaN alloys

N. Nepal, J. Li, M. L. Nakarmi, J. Y. Lin, H. X. Jiang

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Abstract

Deep ultraviolet (UV) photoluminescence emission spectroscopy has been employed to study the exciton localization effect in AlGaN alloys. The temperature dependence of the exciton emission peak energy in Alx Ga1-x N alloys (0≤x≤1) was measured from 10 to 800 K and fitted by the Varshni equation. Deviations of the measured data from the Varshni equation at low temperatures directly provide the exciton localization energies, ELoc. It was found that ELoc increases with x for x≤0.7, and decreases with x for x≥0.8. Our experimental results revealed that for AlGaN alloys, ELoc obtained by the above method has simple linear relations with the localized exciton thermal activation energy and the emission linewidth, thereby established three parallel methods for directly measuring the exciton localization energies in AlGaN alloys. The consequence of strong carrier and exciton localization in AlGaN alloys on the applications of nitride deep UV optoelectronic devices is also discussed.

Original language	English
Article number	062103
Journal	Applied Physics Letters
Volume	88
Issue number	6
DOIs	https://doi.org/10.1063/1.2172728
State	Published - Feb 2006

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title = "Exciton localization in AlGaN alloys",

abstract = "Deep ultraviolet (UV) photoluminescence emission spectroscopy has been employed to study the exciton localization effect in AlGaN alloys. The temperature dependence of the exciton emission peak energy in Alx Ga1-x N alloys (0≤x≤1) was measured from 10 to 800 K and fitted by the Varshni equation. Deviations of the measured data from the Varshni equation at low temperatures directly provide the exciton localization energies, ELoc. It was found that ELoc increases with x for x≤0.7, and decreases with x for x≥0.8. Our experimental results revealed that for AlGaN alloys, ELoc obtained by the above method has simple linear relations with the localized exciton thermal activation energy and the emission linewidth, thereby established three parallel methods for directly measuring the exciton localization energies in AlGaN alloys. The consequence of strong carrier and exciton localization in AlGaN alloys on the applications of nitride deep UV optoelectronic devices is also discussed.",

author = "N. Nepal and J. Li and Nakarmi, {M. L.} and Lin, {J. Y.} and Jiang, {H. X.}",

note = "Funding Information: This research is supported by the DOE (No. 96ER45604).",

year = "2006",

month = feb,

doi = "10.1063/1.2172728",

language = "English",

volume = "88",

journal = "Applied Physics Letters",

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TY - JOUR

T1 - Exciton localization in AlGaN alloys

AU - Nepal, N.

AU - Li, J.

AU - Nakarmi, M. L.

AU - Lin, J. Y.

AU - Jiang, H. X.

N1 - Funding Information: This research is supported by the DOE (No. 96ER45604).

PY - 2006/2

Y1 - 2006/2

N2 - Deep ultraviolet (UV) photoluminescence emission spectroscopy has been employed to study the exciton localization effect in AlGaN alloys. The temperature dependence of the exciton emission peak energy in Alx Ga1-x N alloys (0≤x≤1) was measured from 10 to 800 K and fitted by the Varshni equation. Deviations of the measured data from the Varshni equation at low temperatures directly provide the exciton localization energies, ELoc. It was found that ELoc increases with x for x≤0.7, and decreases with x for x≥0.8. Our experimental results revealed that for AlGaN alloys, ELoc obtained by the above method has simple linear relations with the localized exciton thermal activation energy and the emission linewidth, thereby established three parallel methods for directly measuring the exciton localization energies in AlGaN alloys. The consequence of strong carrier and exciton localization in AlGaN alloys on the applications of nitride deep UV optoelectronic devices is also discussed.

AB - Deep ultraviolet (UV) photoluminescence emission spectroscopy has been employed to study the exciton localization effect in AlGaN alloys. The temperature dependence of the exciton emission peak energy in Alx Ga1-x N alloys (0≤x≤1) was measured from 10 to 800 K and fitted by the Varshni equation. Deviations of the measured data from the Varshni equation at low temperatures directly provide the exciton localization energies, ELoc. It was found that ELoc increases with x for x≤0.7, and decreases with x for x≥0.8. Our experimental results revealed that for AlGaN alloys, ELoc obtained by the above method has simple linear relations with the localized exciton thermal activation energy and the emission linewidth, thereby established three parallel methods for directly measuring the exciton localization energies in AlGaN alloys. The consequence of strong carrier and exciton localization in AlGaN alloys on the applications of nitride deep UV optoelectronic devices is also discussed.

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U2 - 10.1063/1.2172728

DO - 10.1063/1.2172728

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SN - 0003-6951

VL - 88

JO - Applied Physics Letters

JF - Applied Physics Letters

IS - 6

M1 - 062103

ER -

Exciton localization in AlGaN alloys

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