Defect luminescence of GaN grown by pulsed laser deposition

• Published in: Journal of crystal growth Vol. 222; no. 3; pp. 497 - 502
• Main Authors: Mah, K.W, McGlynn, E, Castro, J, Lunney, J.G, Mosnier, J-P, O’Mahony, D, Henry, M.O
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2001; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defect; Defects and impurities: doping, implantation, distribution, concentration, etc; Exact sciences and technology; Gallium nitride; Iii-v semiconductors; Laser deposition; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Pulsed laser deposition; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; 78.55.Cr; Photoluminescence; Defect; Pulsed laser deposition; 81.15.Fg; Gallium nitride; 61.72.Hh; 81.05.Ea; Crystal defects; Inorganic compounds; Semiconductor materials; Gallium nitrides; Crystal growth from vapors; XRD; Experimental study; Pulsed lasers; Thin films; Nitrides; Laser ablation technique; III-V semiconductors
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(00)00963-5

GaN films with ∼0.4 μm thickness, without any intentional buffer layer, have been successfully grown on a sapphire (0 0 0 1) substrate by pulsed laser deposition (PLD) in a nitrogen atmosphere. Material quality is investigated using low temperature photoluminescence (PL) (which yields a line-width of 15 meV for the donor-bound exciton (D–X) transitions) and X-ray diffraction (XRD) measurements. Activation energies of 26.5 and 230 meV derived from the temperature dependence PL studies of the donor–acceptor (D–A) transitions are consistent with previous studies. In addition, two values of activation energy (i.e. 13.5 and 25 meV) for the 3.41 eV peak were observed in the low- and high- temperature regimes. We discuss these data in terms of the possible mixed cubic/hexagonal phase structure of the material, and examine evidence for the localisation of the electrons and holes in the different phases.