中国物理B ›› 2010, Vol. 19 ›› Issue (8): 86106-086106.doi: 10.1088/1674-1056/19/8/086106

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Effect of high temperature annealing on strain and band gap of GaN nanoparticles

毛宏志1, 肖洪地2, 林兆军2, 马洪磊2   

  1. (1)School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China; (2)School of Physics, Shandong University, Jinan 250100, China
  • 收稿日期:2009-03-23 修回日期:2010-02-01 出版日期:2010-08-15 发布日期:2010-08-15
  • 基金资助:
    Project supported by the Excellent Young Scientist Awarding Fund of Shandong Province, China (Grant No. 2008BS04005), the China Postdoctoral Science Foundation (Grant No. 20080441141), and the Postdoctoral Innovation Program Special Fund of Shandong Province, China (Grant No. 200803054).

Effect of high temperature annealing on strain and band gap of GaN nanoparticles

Xiao Hong-Di(肖洪地)a)† , Mao Hong-Zhi(毛宏志)b), Lin Zhao-Jun(林兆军)a), and Ma Hong-Lei(马洪磊)a)   

  1. a School of Physics, Shandong University, Jinan 250100, China; b School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
  • Received:2009-03-23 Revised:2010-02-01 Online:2010-08-15 Published:2010-08-15
  • Supported by:
    Project supported by the Excellent Young Scientist Awarding Fund of Shandong Province, China (Grant No. 2008BS04005), the China Postdoctoral Science Foundation (Grant No. 20080441141), and the Postdoctoral Innovation Program Special Fund of Shandong Province, China (Grant No. 200803054).

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摘要： Black-coloured GaN nanoparticles with an average grain size of 50 nm have been obtained by annealing GaN nanoparticles under flowing nitrogen at 1200 oC for 30 min. XRD measurement result indicates an increase in the lattice parameter of the GaN nanoparticles annealed at 1200 oC, and HRTEM image shows that the increase cannot be ascribed to other ions in the interstitial positions. If the as-synthesised GaN nanoparticles at 950 oC are regarded as standard, the thermal expansion changes nonlinearly with temperature and is anisotropic; the expansion below 1000oC is smaller than that above 1000 oC. This study provides an experimental demonstration for selecting the proper annealing temperature of GaN. In addition, a large blueshift in optical bandgap of the annealed GaN nanoparticles at 1200 oC is observed, which can be ascribed to the dominant transitions from the C(Γ7) with the peak energy at 3.532 eV.

Abstract: Black-coloured GaN nanoparticles with an average grain size of 50 nm have been obtained by annealing GaN nanoparticles under flowing nitrogen at 1200 $^\circ$C for 30 min. XRD measurement result indicates an increase in the lattice parameter of the GaN nanoparticles annealed at 1200 $^\circ$C, and HRTEM image shows that the increase cannot be ascribed to other ions in the interstitial positions. If the as-synthesised GaN nanoparticles at 950 $^\circ$C are regarded as standard, the thermal expansion changes nonlinearly with temperature and is anisotropic; the expansion below 1000 $^\circ$C is smaller than that above 1000 $^\circ$C. This study provides an experimental demonstration for selecting the proper annealing temperature of GaN. In addition, a large blueshift in optical bandgap of the annealed GaN nanoparticles at 1200 $^\circ$C is observed, which can be ascribed to the dominant transitions from the C($\Gamma$7) with the peak energy at 3.532 eV.

Key words: GaN nanoparticles, thermal expansion, strain, blue shift, bandgap

中图分类号:  (Kinetics of defect formation and annealing)

  • 61.72.Cc
61.46.Df (Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)) 61.72.J- (Point defects and defect clusters) 71.20.Nr (Semiconductor compounds) 78.55.Cr (III-V semiconductors)