Long-lived Single Excitons, Trions, and Biexcitons in CdSe/CdTe Type-II Colloidal Quantum WeIls

doi:10.1063/1674-0068/30/cjcp1711206

	Long-lived Single Excitons, Trions, and Biexcitons in CdSe/CdTe Type-II Colloidal Quantum WeIls
	Wang, Jun-hui ; Liang, Gui-jie ; Wu, Kai-feng 1
刊名	CHINESE JOURNAL OF CHEMICAL PHYSICS
	2017-12-01
卷号	30 期号:6 页码:649-656
关键词	Solar Energy Excited State Lifetime Exciton Trion Biexciton Type-ii Quantum Wells Nanoplatelets Auger Recombination
ISSN号	1674-0068
DOI	10.1063/1674-0068/30/cjcp1711206
文献子类	Article
英文摘要	Light-harvesters with long-lived excited states are desired for efficient solar energy conversion systems. Many solar-to-fuel conversion reactions, such as H-2 evolution and CO2 reduction, require multiple sequential electron transfer processes, which leads to a complicated situation that excited states involves not only excitons (electron-hole pairs) but also multi-excitons and charged excitons. While long-lived excitons can be obtained in various systems (e.g., semiconductor nanocrystals), multi-excitons and charged excitons are typically shorted-lived due to nonradiative Auger recombination pathways whereby the recombination energy of an exciton is quickly transferred to the third carrier on a few to hundreds of picoseconds timescale. In this work, we report a study of excitons, trions (an exciton plus an additional charge), and biexcitons in CdSe/CdTe colloidal quantum wells or nanoplatelets. The type II band alignment effectively separates electrons and holes in space, leading to a single exciton lifetime of 340 ns which is 2 order of magnitudes longer than that in plane CdSe nanoplatelets. More importantly, the electron-hole separation also dramatically slows down Auger decay, giving rise to a trion lifetime of 70 ns and a biexciton lifetime of 11 ns, among the longest values ever reported for colloidal nanocrystals. The long-lived exciton, trion, and biexciton states, combined with the intrinsically strong light-absorption capability of two-dimensional systems, enable the CdSe/CdTe type-II nanoplatelets as promising light harvesters for efficient solar-to-fuel conversion reactions.
WOS关键词	ULTRAFAST CHARGE SEPARATION ; SOLAR-ENERGY CONVERSION ; SEMICONDUCTOR NANOCRYSTALS ; AUGER RECOMBINATION ; CARRIER MULTIPLICATION ; ACCEPTOR COMPLEXES ; ELECTRON-TRANSFER ; SIZE DEPENDENCE ; OPTICAL GAIN ; DOTS
WOS研究方向	Physics
语种	英语
出版者	CHINESE PHYSICAL SOC
WOS记录号	WOS:000423287900008
内容类型	期刊论文
源URL	[http://cas-ir.dicp.ac.cn/handle/321008/168576]
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	Wu, Kai-feng
作者单位	1.Chinese Acad Sci, Dalian Inst Chem Phys, State Key Lab Mol React Dynam, Dalian 116023, Peoples R China 2.Chinese Acad Sci, Dalian Inst Chem Phys, Collaborat Innovat Ctr Chem Energy Mat iChEM, Dalian 116023, Peoples R China
推荐引用方式 GB/T 7714	Wang, Jun-hui,Liang, Gui-jie,Wu, Kai-feng. Long-lived Single Excitons, Trions, and Biexcitons in CdSe/CdTe Type-II Colloidal Quantum WeIls[J]. CHINESE JOURNAL OF CHEMICAL PHYSICS,2017,30(6):649-656.
APA	Wang, Jun-hui,Liang, Gui-jie,&Wu, Kai-feng.(2017).Long-lived Single Excitons, Trions, and Biexcitons in CdSe/CdTe Type-II Colloidal Quantum WeIls.CHINESE JOURNAL OF CHEMICAL PHYSICS,30(6),649-656.
MLA	Wang, Jun-hui,et al."Long-lived Single Excitons, Trions, and Biexcitons in CdSe/CdTe Type-II Colloidal Quantum WeIls".CHINESE JOURNAL OF CHEMICAL PHYSICS 30.6(2017):649-656.