中国物理B ›› 2009, Vol. 18 ›› Issue (5): 2002-2005.doi: 10.1088/1674-1056/18/5/045

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Scattering behaviours to the two-dimensional electron gasinduced by the Al composition fluctuation in AlxGa1-xNbarrier in AlxGa1-xN/GaN heterostructures

王彦, 沈波, 许福军, 黄森, 苗振林, 林芳, 杨志坚, 张国义   

  1. State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
  • 收稿日期:2008-11-17 修回日期:2008-12-19 出版日期:2009-05-20 发布日期:2009-05-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10774001, 60736033 and 60628402), and National Basic Research Program of China (Grant Nos 2006CB604908 and 2006CB921607).

Scattering behaviour of a two-dimensional electron gas induced by Al composition fluctuation in AlxGa1-x Nbarrier in AlxGa1-xN/GaN heterostructures

Wang Yan(王彦), Shen Bo(沈波)†, Xu Fu-Jun(许福军), Huang Sen(黄森), Miao Zhen-Lin(苗振林), Lin Fang(林芳), Yang Zhi-Jian(杨志坚), and Zhang Guo-Yi(张国义)   

  1. State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
  • Received:2008-11-17 Revised:2008-12-19 Online:2009-05-20 Published:2009-05-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10774001, 60736033 and 60628402), and National Basic Research Program of China (Grant Nos 2006CB604908 and 2006CB921607).

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摘要： This paper reports that cathodoluminescence (CL) measurements have been done to study the alloy fluctuation of the Al0.3Ga0.7N layer in Al0.3Ga0.7N/GaN heterostructures. The CL images and linescanning results demonstrate the existence of compositional fluctuation of Al in the Al0.3Ga0.7N barrier. A model using a δ -shape perturbation Hamilton function has been proposed to simulate the scattering probability of the two dimensional electron gases (2DEG) induced by Al composition fluctuation. Two factors, including conduction band fluctuation and polarization electric field variation, induced by the Al composition fluctuation have been taken into account. The scattering relaxation time induced by both factors has been estimated to be 0.31~ns and 0.0078~ns, respectively, indicating that the variation of the piezoelectric field is dominant in the scattering of the 2DEG induced by Al fluctuation.

关键词: scattering, cathodoluminescence, fluctuation

Abstract: This paper reports that cathodoluminescence (CL) measurements have been done to study the alloy fluctuation of the Al0.3Ga0.7N layer in Al0.3Ga0.7N/GaN heterostructures. The CL images and linescanning results demonstrate the existence of compositional fluctuation of Al in the Al0.3Ga0.7N barrier. A model using a $\delta$-shape perturbation Hamilton function has been proposed to simulate the scattering probability of the two dimensional electron gases (2DEG) induced by Al composition fluctuation. Two factors, including conduction band fluctuation and polarization electric field variation, induced by the Al composition fluctuation have been taken into account. The scattering relaxation time induced by both factors has been estimated to be 0.31 ns and 0.0078 ns, respectively, indicating that the variation of the piezoelectric field is dominant in the scattering of the 2DEG induced by Al fluctuation.

Key words: scattering, cathodoluminescence, fluctuation

中图分类号:  (III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions)

  • 73.40.Kp
72.10.Fk (Scattering by point defects, dislocations, surfaces, and other imperfections (including Kondo effect)) 78.60.Hk (Cathodoluminescence, ionoluminescence) 77.65.-j (Piezoelectricity and electromechanical effects)