Suppression of nonradiative recombination in ionic insulators by defects: Role of fast electron trapping in Tl-doped CsI

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	Suppression of nonradiative recombination in ionic insulators by defects: Role of fast electron trapping in Tl-doped CsI
	Bang, J ; Wang, Z ; Gao, F ; Meng, S ; Zhang, SB
刊名	PHYSICAL REVIEW B
	2013
卷号	87 期号:20
ISSN号	1098-0121
通讯作者	Bang, J (reprint author), Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA.
中文摘要	In semiconductors, defects often assist nonradiative relaxation. However, Tl doping can significantly suppress the nonradiative relaxation in alkali halides to increase scintillation efficiency. Without the Tl, it is known that the creation of Frenkel pairs at self-trapped excitons, assisted by excited electron and hole relaxations, is the reason for the nonradiative relaxation. Here we show by first-principles calculation that Tl doping introduces Tl p states inside the band gap to trap the excited electrons. The trapping is highly effective to within several picoseconds, as revealed by time-dependent density functional theory calculations. It alters the nonradiative relaxation process to result in a noticeable increase in the relaxation barrier from 0.3 to 0.63 eV, which reduces the nonradiative relaxation by roughly a factor of 10(5) at room temperature.
资助信息	National Nuclear Security Administration, Office of Nuclear Nonproliferation Research and Engineering [NA-22]; US Department of Energy; Computational Center for Nanotechnology Innovations at RPI; US Department of Energy's Office of Biological and Environmental Research; NSFC [11074287, 11222431]; MOST [2012CB921403]
语种	英语
公开日期	2014-01-17
内容类型	期刊论文
源URL	[http://ir.iphy.ac.cn/handle/311004/57522]
专题	物理研究所_物理所公开发表论文_物理所公开发表论文_期刊论文
推荐引用方式 GB/T 7714	Bang, J,Wang, Z,Gao, F,et al. Suppression of nonradiative recombination in ionic insulators by defects: Role of fast electron trapping in Tl-doped CsI[J]. PHYSICAL REVIEW B,2013,87(20).
APA	Bang, J,Wang, Z,Gao, F,Meng, S,&Zhang, SB.(2013).Suppression of nonradiative recombination in ionic insulators by defects: Role of fast electron trapping in Tl-doped CsI.PHYSICAL REVIEW B,87(20).
MLA	Bang, J,et al."Suppression of nonradiative recombination in ionic insulators by defects: Role of fast electron trapping in Tl-doped CsI".PHYSICAL REVIEW B 87.20(2013).