Temperature and composition dependent excitonic luminescence and exciton-phonon coupling in CdSeS nanocrystals

doi:10.1186/1556-276X-7-301

	Temperature and composition dependent excitonic luminescence and exciton-phonon coupling in CdSeS nanocrystals
	Gao,Yachen 1; Wu,Wenzhi 1; Chang,Qing 1; Ye,Hong-an 1; Yu,Dongqi 2
刊名	Nanoscale Research Letters
	2012-06-08
卷号	7 期号:1
关键词	71.35.Aa 71.55.Gs 78.47.jd 78.67.Hc.
ISSN号	1556-276X
DOI	10.1186/1556-276X-7-301
通讯作者	Chang,Qing(changqinghit@yahoo.com.cn)
英文摘要	AbstractThe yellow- and red-emitting CdSeS nanocrystals (NCs) synthesized through one-step organometallic synthesis method are uniformly assembled in polymethyl methacrylate (PMMA). A higher-energy emission band originates from band-edge excitonic state appeared at low temperature. With the Se dopant concentration increasing, the luminescent spectra of CdSeS NCs have a red-shifted emission peak and a shorter luminescent lifetime, which is attributed to the existence of trapping state caused by surface defect and Se dopant. CdSeS NC shows a shorter luminescence lifetime and higher energy emission peak in PMMA matrix than that in toluene, indicating that the former is more favorable to transfer energy through exciton-phonon coupling. The upconversion luminescence (UCL) is observed using 800?nm femtosecond laser excitation. The pump power dependence demonstrated UCL spectra of yellow-emitting CdSeS NCs has a slope of 2.2, while that of red-emitting CdSeS NCs has a slope of 1.4. The results demonstrate that the two-photon absorption plays a dominating role when Se concentration of CdSeS NCs is lower, while phonon-assisted UCL by one-photon excitation gradually takes place with the amount of Se dopants increasing.
语种	英语
出版者	Springer New York
WOS记录号	BMC:10.1186/1556-276X-7-301
内容类型	期刊论文
源URL	[http://cas-ir.dicp.ac.cn/handle/321008/167100]
专题	大连化学物理研究所_中国科学院大连化学物理研究所
通讯作者	Chang,Qing
作者单位	1.Heilongjiang University; School of Electronic Engineering 2.Liaoning Normal University; School of Physics and Electronic Technology
推荐引用方式 GB/T 7714	Gao,Yachen,Wu,Wenzhi,Chang,Qing,et al. Temperature and composition dependent excitonic luminescence and exciton-phonon coupling in CdSeS nanocrystals[J]. Nanoscale Research Letters,2012,7(1).
APA	Gao,Yachen,Wu,Wenzhi,Chang,Qing,Ye,Hong-an,&Yu,Dongqi.(2012).Temperature and composition dependent excitonic luminescence and exciton-phonon coupling in CdSeS nanocrystals.Nanoscale Research Letters,7(1).
MLA	Gao,Yachen,et al."Temperature and composition dependent excitonic luminescence and exciton-phonon coupling in CdSeS nanocrystals".Nanoscale Research Letters 7.1(2012).