Relationship between Sample Morphology and Carrier Diffusion Length in GaN Thin Films
M. Godlewskia, E.M. Goldysb, M. Phillipsc, T. Böttcherd, S. Figged, D. Hommeld, R. Czerneckie, P. Prystawkoe, M. Leszczynskie, P. Perline, P. Wisniewskie, T. Suskie, M. Bockowskie, I. Grzegorye and S. Porowskie
aInstitute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
bSemicond. Sci. and Technol. Lab., Macquarie Univ., Sydney, Australia
cMicrostructural Analysis Unit, University of Technology Sydney, Australia
dInstitute of Solid State Physics, Bremen University, Germany
eHigh Pressure Res. Center (Unipress), Polish Acad. Sci., Warsaw, Poland
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Scanning and spot-mode cathodoluminescence investigations of homo- and hetero-epitaxial GaN films indicate a surprisingly small influence of their microstructure on overall intensity of a light emission. This we explain by a correlation between structural quality of these films and diffusion length of free carriers and excitons. Diffusion length increases with improving structural quality of the samples, which, in turn, enhances the rate of nonradiative recombination on structural defects, such as dislocations.
DOI: 10.12693/APhysPolA.102.627
PACS numbers: 61.72.Ff, 61.72.Mm, 68.37.Hk, 78.60.Hk