Journal of Crystal Growth 278 (2005) 406–410 Influence of dislocation density on photoluminescence intensity of GaN J.F. Fa¨lth a,Ã , M.N. Gurusinghe a , X.Y. Liu a , T.G. Andersson a , I.G. Ivanov b , B. Monemar b , H.H. Yao c , S.C. Wang c a Department of Microtechnology and Nanoscience, Applied Semiconductor Physics-MBE, Chalmers University of Technology and Go¨teborg University, Go¨teborg S-412 96, Sweden b Department of Physics and Measurement Technology, Linko¨ping University, S-581 83 Linko¨ping, Sweden c Institute of Electro-optical Engineering, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan Available online 11 February 2005 Abstract The influence of dislocation density on photoluminescence intensity is investigated experimentally and compared to a model. GaN samples were grown by molecular beam epitaxy and metal-organic chemical vapour deposition. Different growth parameters and thicknesses of the layers resulted in different dislocation densities. The threading dislocation density, measured by atomic force microscopy, scanning electron microscopy and X-ray diffraction, covered a range from 5  10 8 to 3  10 10 cm 2 . Carrier concentration was measured by capacitance–voltage-, and Hall effect measurements and photoluminescence at 2 K was recorded. A model which accounts for the photoluminescence intensity as a function of dislocation density and carrier concentration in GaN is developed. The model shows good agreement with experimental results for typical GaN dislocation densities, 5  10 8 –1  10 10 cm 2 , and carrier concentrations 4  10 16 –1  10 18 cm 3 . r 2005 Elsevier B.V. All rights reserved. PACS: 81.15.Hi; 78.20.Bh; 61.72.Hh Keywords: A3. Molecular beam epitaxy; B1. Nitrides; A1. Defects; A1. Photoluminescence; A1. Capacitance–voltage measurement; A1. Atomic force microscopy 1. Introduction The components of the group III nitride system and their alloys are attractive materials for use in optoelectronic and high-temperature, high-power electronic applications. The wide bandgap and the excellent thermal- and chemical stability make ARTICLE IN PRESS www.elsevier.com/locate/jcrysgro 0022-0248/$ - see front matter r 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.jcrysgro.2005.01.010 Ã Corresponding author. Tel.: +46 31 7723226; fax: +46 31 7723085. E-mail address: fredrik.falth@mc2.chalmers.se (J.F. Fa¨ lth).