Acta Chim. Sinica ›› 2016, Vol. 74 ›› Issue (4): 330-334.DOI: 10.6023/A15120785 Previous Articles     Next Articles



陈美华a, 潘峥a, 尹月锋a, 刘洁a, 刘梦媛a, 贾紫君a, 梁桂杰a,b   

  1. a. 低维光电材料与器件湖北省重点实验室 湖北文理学院物理与电子工程学院 襄阳 441053;
    b. Department of Chemistry, Emory University, Atlanta 30322, USA
  • 投稿日期:2015-12-17 发布日期:2016-03-22
  • 通讯作者: 梁桂杰
  • 基金资助:

    项目受国家自然科学基金(No. 51502085)和湖北省自然科学基金(No. 2013CFB064)资助.

Panchromatic and High-efficient Energy Transfer Assembly Based on Type I Core-shell Quantum Dots

Chen Meihuaa, Pan Zhenga, Yin Yuefenga, Liu Jiea, Liu Mengyuana, Jia Zijuna, Liang Guijiea,b   

  1. a Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, School of Physics and Electronic Engineering, Hubei University of Arts and Science, Xiangyang 441053;
    b Department of Chemistry, Emory University, Atlanta, GA 30322, USA
  • Received:2015-12-17 Published:2016-03-22
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 51502085) and Natural Science Foundation of Hubei Province (No. 2013CFB064).

In order to overcome the low energy transfer efficiency of the conventional FRET (Förster resonance energy transfer) system, a novel spectra-matching and distance-controllable CIS@ZnS-SQ FRET assembly has been prepared via ultrasonic self-assembly method, by using the synthesized visible CIS@ZnS type I core-shell quantum dots as energy donor and the near infrared SQ dyes as acceptor. Through controllable synthesis of quantum dots, the absorption and fluorescence performance of FRET system were adjusted by the size of CIS@ZnS, while the distance of energy donor-acceptor and the non-valid charge recombination in the FRET system were controlled by the wide-band shell of quantum dots. The excitons transfer and recombination kinetics in CIS@ZnS-SQ assembly were investigated by the pump-probe femtosecond ultrafast transient absorption measurements, with which results in the FRET-type energy transfer mechanism: CIS*+SQ→CIS+SQ* has been proven and a high energy transfer rate of about 5.0×1010 s-1 has been gained between CIS@ZnS and SQ. The excitons' lifetime and FRET energy transfer efficiency were calculated from the fluorescence decay kinetic curves tested by time-resolved fluorescence measurements. The results show that the energy transfer in CIS@ZnS-SQ depends on the size of CIS@ZnS quantum dots. As the size of CIS@ZnS (mainly refers to the ZnS shell thickness) increases from 2.1±0.4 nm to 2.9±0.4 nm, 4.1±0.3 nm, 5.4±0.5 nm and 7.2±0.5 nm, the fluorescence quantum yield of CIS@ZnS improves from 5.4% to 26%, 33%, 38% and 43.3% as well as the distance between CIS@ZnS and SQ (energy donor and acceptor) increases gradually, which makes the FRET energy transfer efficiency (ηFRET) first rise and then decline. As a result, an optimal ηFRET value of 62.8% was gained in the FRET assembly when the reaction time of ZnS shell was 20 min. This research will have a promising theoretical and practical value for the development of the panchromatic and high-efficiency solar cells.

Key words: type I quantum dots, near-infrared dye, wide spectral response, energy transfer, exciton quenching