Free excitons in strained MOCVD-grown GaN layers
N.N. Syrbu, I.M. Tiginyanu, V.V. Ursaki, V.V. Zalamai
Technical University of Moldova
Veaceslav Popa , S.M. Hubbard, Dimitris Pavlidis
The University of Michigan
This article was received on Tuesday, November 26, 2002 and
accepted on Monday, February 3, 2003. Abstract
GaN
layers grown on sapphire substrates were characterized using high resolution
optical reflectivity and absorption spectroscopy in the region of ground and
excited exciton states. The main exciton parameters are deduced from
calculations of reflectivity contours for A and B exciton S-states. The
parameters of the
5 state of the A-exciton as well as those
of the
5 and
1 states of the B-exciton are
determined from a comparative analysis of reflectivity and absorption spectra
in thin layers. The influence of strains inherent to MOCVD-grown GaN layers on
the exciton parameters including effective masses and longitudinal-transverse
splitting is discussed. Electron transitions from the three
(
9,
7,
7) upper valence
bands to the second Ec2 conduction band of
3
symmetry were evidenced.Outline
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Cite this article as: MRS Internet J. Nitride Semicond. Res. 8, 1(2003).
last updated Monday, February 10, 2003 4:03:29 PM.© 2003 The Materials Research Society
