TITLE

Impact of ultraviolet-laser heating on the photoluminescence of ensembles of GaN microcrystallites

AUTHOR(S)
Bergman, Leah; Chen, Xiang-Bai; Feldmeier, Joel; Purdy, Andrew P.
PUB. DATE
July 2003
SOURCE
Applied Physics Letters;7/28/2003, Vol. 83 Issue 4, p764
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
We present optical analysis concerning the redshift of the photoluminescence (PL) of ensembles of GaN microcrystals. We found that the extent of the redshift depends on the laser power as well as on the size of the ensemble. For ensembles of ∼30 µm, the laser power in our experimental specification impacted the PL energy and caused a redshift of up to 120 meV. This phenomenon was not observed for a small ensemble of ∼1 µm or less. For the small ensemble, the PL redshift was negligible and depended weakly on the laser power; similar behavior was found in GaN thin film. The above findings were observed in the PL of GaN microcrystalline of wurtzite as well as the cubic structure. Our results point to a laser heating event occurring in the large ensemble; the emitted scattered light is confined among the microcrystallites thus causing heating. For a small ensemble, the light has a higher probability of diffusing outside the enclosure, and thus no laser heating occurs.
ACCESSION #
10331061

 

Related Articles

  • Exciton diffusion length in microcrystalline chlorophyll a. Nasr, Chouhaid; Taleb, Toufik; Leblanc, Roger M.; Hotchandani, Surat // Applied Physics Letters;9/23/1996, Vol. 69 Issue 13, p1823 

    The measurements of photocurrent as a function of depletion layer or Schottky barrier width have been performed to determine the exciton diffusion length (L) in microcrystalline chlorophyll a (Chl a). This method of determining L is particularly advantageous in that it does not require a prior...

  • Epitaxial ZnO films on (111) Si substrates with Sc2O3 buffer layers. Guo, W.; Katz, M. B.; Nelson, C. T.; Heeg, T.; Schlom, D. G.; Liu, B.; Che, Y.; Pan, X. Q. // Applied Physics Letters;3/23/2009, Vol. 94 Issue 12, p122107 

    Epitaxial (0001) ZnO films were grown on (111) Si substrates using epitaxial (111) Sc2O3 buffer layers. The quality of the ZnO epilayers is manifested by a Hall mobility of 77 cm2/V s at room temperature, x-ray diffraction rocking curve full widths at half maximum of 300–400 arc sec, and...

  • Study on the quantum confinement effect on ultraviolet photoluminescence of crystalline ZnO nanoparticles with nearly uniform size. Fu, Z. D.; Cui, Y. S.; Zhang, S. Y.; Chen, J.; Yu, D. P.; Zhang, S. L.; Niu, L.; Jiang, J. Z. // Applied Physics Letters;6/25/2007, Vol. 90 Issue 26, p263113 

    Crystalline ZnO nanoparticles with nearly uniform size were studied using photoluminescence and Raman spectroscopy. The main spectral feature of ultraviolet photoluminescence is attributed to the recombination of free exciton (FX) and the first surface phonon replica of FX emission. The energy...

  • Quantum confinement of excitons in dendrite-like GaN nanowires. Ghosh, R.; Basak, D. // Journal of Applied Physics;10/15/2005, Vol. 98 Issue 8, p086104 

    Dendrite-like GaN nanowires have been grown by direct reaction of gallium metal with ammonia without any catalyst in a simple grinding-mediated two-step process, the second step being annealing of the as-synthesized GaN powder at 800 °C. The samples have been characterized by x-ray...

  • Electron microscopy and microanalysis of a YBa2Cu3Ox superconducting oxide. Dou, S. X.; Bourdillon, A. J.; Sorrell, C. C.; Ringer, S. P.; Easterling, K. E.; Savvides, N.; Dunlop, J. B.; Roberts, R. B. // Applied Physics Letters;8/17/1987, Vol. 51 Issue 7, p535 

    The onset of superconductivity at 140 K has been observed in the high Tc Y-Ba-Cu-O system in samples consisting of 90% by volume of a single-phase oxide of average cation ratio Y:Ba:Cu[bar_over_tilde:_approx._equal_to]1:2:3. A sharp superconducting transition in the resistivity has been...

  • Microcrystalline silicon formation by silicon nanoparticles. Schierning, G.; Theissmann, R.; Wiggers, H.; Sudfeld, D.; Ebbers, A.; Franke, D.; Witusiewicz, V. T.; Apel, M. // Journal of Applied Physics;Apr2008, Vol. 103 Issue 8, p084305 

    Thin silicon films are of great importance for large-area electronic applications, for example, as the basis for switching electronics in flat-panel display devices or as the active layer of solar cells. In this paper, we show that silicon nanoparticles have the potential to be used as raw...

  • Protein-Coated Microcrystals of Pseudomonas aeruginosa PseA lipase. Ruchi Gaur; G. Gupta; M. Vamsikrishnan; S. Khare // Applied Biochemistry & Biotechnology;Dec2008, Vol. 151 Issue 2/3, p160 

    Abstract  Highly active Pseudomonas aeruginosa lipase protein-coated microcrystals (PAL PCMC) have been prepared by immobilization of protein onto K2SO4 as excipient solid support carrier and n-propanol as precipitating solvent. Transmission electron micrographs confirmed the...

  • Anomalous change of extinction spectra of CuCl microcrystals. Masumoto, Yasuaki; Wamura, Tetsuro // Applied Physics Letters;5/20/1991, Vol. 58 Issue 20, p2270 

    Studies the optical transmission spectra of CuCl microcrystals embedded in NaCl crystals around the Z[sub 3] exciton resonance by varying the annealing time. Extinction spectra of the Z[sub 3] exciton change; Use of the Mie theory to explain the spectral change due to the growth of microcrystals.

  • Photoluminescence in strained InGaAs/GaAs superlattices. Dahl, D. A.; Dries, L. J.; Junga, F. A.; Opyd, W. G.; Chu, P. // Journal of Applied Physics;3/1/1987, Vol. 61 Issue 5, p2079 

    Presents information on a study which analyzed experimental results for photoluminescence and transmission electron microscopy of a pseudomorphic ten period superlattice with x = indium concentration of 0.13. Peak position results; Theoretical interpretation of the low-temperature; Linear...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics