Exciton spectra of AlN epitaxial films

T. Onuma, S. F. Chichibu, Takayuki Sota, K. Asai, S. Sumiya, T. Shibata, M. Tanaka

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Excitonic resonance energies in a C-plane AlN epilayer on the (0001) sapphire substrate grown by low-pressure metalorganic vapor phase epitaxy were determined as a function of temperature by means of optical reflectance (OR) and cathodoluminescence (CL) measurements. The OR spectra exhibited distinct reflectance anomalies at the photon energies just above the multiple internal reflection fringes, and the spectral lineshape was fitted considering A (Γ 7v u → Γ 7c) and BC (Γ 9v, Γ 7v l → Γ 7c) exciton transitions. The energies them at 0 K were obtained to be 6.211 and 6.266 eV, giving the crystal field splitting (Δ cr) of approximately 55 meV. The AlN film exhibited an excitonic emission even at 300 K, which is due to the small Bohr radius of excitons and large longitudinal optical phonon energies. The Einstein characteristic temperature Θ E was estimated to be 580 K.

Original languageEnglish
Title of host publicationMaterials Research Society Symposium - Proceedings
EditorsJ.E. Northrup, J. Neugebauer, D.C. Look, S.F. Chichibu, H. Riechert
Number of pages6
Publication statusPublished - 2002
Externally publishedYes
EventGaN and Related Alloys-2001 - Boston, MA, United States
Duration: 2001 Nov 262001 Nov 30


OtherGaN and Related Alloys-2001
CountryUnited States
CityBoston, MA


ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Onuma, T., Chichibu, S. F., Sota, T., Asai, K., Sumiya, S., Shibata, T., & Tanaka, M. (2002). Exciton spectra of AlN epitaxial films. In J. E. Northrup, J. Neugebauer, D. C. Look, S. F. Chichibu, & H. Riechert (Eds.), Materials Research Society Symposium - Proceedings (Vol. 693, pp. 515-520)