Charge separation in type II tunneling structures of close-packed CdTe and CdSe nanocrystals

被引:73
作者
Gross, Dieter
Susha, Andrei S.
Klar, Thomas A.
Da Como, Enrico
Rogach, Andrey L. [1 ]
Feldmann, Jochen
机构
[1] Univ Munich, Photon & Optoelect Grp, Dept Phys, D-80799 Munich, Germany
关键词
D O I
10.1021/nl080489a
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
We report on charge separation between type II aligned CdTe and CdSe nanocrystals. Two types of electrostatically bound nanocrystal structures have been studied: first, clusters of nanocrystals hold together by Ca(II) ions in aqueous solution and, second, thin film structures of nanocrystals created with layer-by-layer deposition in combination with polyelectrolytes. In both types of structures, short interparticle distances of less than I nm have been achieved, whereby the isolating organic ligands on the nanocrystal surfaces and/or the polymer monolayers act as tunneling barriers between nanocrystals. We have observed an efficient quenching of photoluminescence and a reduced emission lifetime for CdTe nanocrystals in both types of type II heterostructures. This result is explained by a spatial charge separation of the photoexcited electron-hole pairs due to tunneling of charge carriers through the thin organic layer between CdTe and CdSe nanocrystals. Type II heterostructures demonstrated here may find future applications in photovoltaics.
引用
收藏
页码:1482 / 1485
页数:4
相关论文
共 33 条
[1]   The use of nanocrystals in biological detection [J].
Alivisatos, P .
NATURE BIOTECHNOLOGY, 2004, 22 (01) :47-52
[2]   Semiconductor nanocrystals photosensitize C60 crystals [J].
Biebersdorf, Andreas ;
Dietmuller, Roland ;
Susha, Andrei S. ;
Rogach, Andrey L. ;
Poznyak, Sergey K. ;
Talapin, Dmitri V. ;
Weller, Horst ;
Klar, Thomas A. ;
Feldmann, Jochen .
NANO LETTERS, 2006, 6 (07) :1559-1563
[3]  
Brabec CJ, 2001, ADV FUNCT MATER, V11, P15, DOI 10.1002/1616-3028(200102)11:1<15::AID-ADFM15>3.0.CO
[4]  
2-A
[5]   Type-II CdSe/CdTe/ZnTe (core-shell-shell) quantum dots with cascade band edges: The separation of electron (at CdSe) and hole (at ZnTe) by the CdTe layer [J].
Chen, CY ;
Cheng, CT ;
Lai, CW ;
Hu, YH ;
Chou, PT ;
Chou, YH ;
Chiu, HT .
SMALL, 2005, 1 (12) :1215-1220
[6]   Electroluminescence from single monolayers of nanocrystals in molecular organic devices [J].
Coe, S ;
Woo, WK ;
Bawendi, M ;
Bulovic, V .
NATURE, 2002, 420 (6917) :800-803
[7]   Spectrally resolved dynamics of energy transfer in quantum-dot assemblies: Towards engineered energy flows in artificial materials [J].
Crooker, SA ;
Hollingsworth, JA ;
Tretiak, S ;
Klimov, VI .
PHYSICAL REVIEW LETTERS, 2002, 89 (18)
[8]   Fuzzy nanoassemblies: Toward layered polymeric multicomposites [J].
Decher, G .
SCIENCE, 1997, 277 (5330) :1232-1237
[9]   Physicochemical evaluation of the hot-injection method, a synthesis route for monodisperse nanocrystals [J].
Donegá, CD ;
Liljeroth, P ;
Vanmaekelbergh, D .
SMALL, 2005, 1 (12) :1152-1162
[10]   Confinement-induced versus correlation-induced electron localization and wave function entanglement in semiconductor nano dumbbells [J].
Franceschetti, A. ;
Wang, L. W. ;
Bester, G. ;
Zunger, A. .
NANO LETTERS, 2006, 6 (05) :1069-1074