Energy gap in GaN bulk single crystal between 293 and 1237 K

• Published in: Journal of crystal growth Vol. 235; no. 1; pp. 111 - 114
• Main Authors: Su, Ching-Hua, Palosz, W., Zhu, Shen, Lehoczky, S.L., Grzegory, I., Perlin, P., Suski, T.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-2002; Elsevier
• Subjects: B1. Nitrides; B2. Semiconducting gallium compounds; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity); Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; B1. Nitrides; B2. Semiconducting gallium compounds; 78.40.Fy; 81.05.Ea; Temperature dependence; Energy gap; Crystal defects; Inorganic compounds; Semiconductor materials; Gallium nitrides; Absorption spectra; Experimental study; Heat treatments; Absorption edge
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(01)01834-6

Optical transmission measurements were performed on GaN bulk single-crystal platelet at temperatures between 293 and 1237
K. The energy bandgaps were determined from the corresponding optical absorption spectra. The bandgaps can be fit well as a function of temperature using the Varshni expression as
E
g
(
eV)=3.556−9.9×10
−4T
2
(T+600).
The shapes of the measured absorption edges were found to be dependent on the thermal treatments of the sample.