CAJ | 학술논문

利用超快光谱技术系统研究了在丁胺包裹的CdSe量子点敏化的TiO2纳米晶薄膜起始时刻界面间电子转移动力学。与之前的报道不同，该实验结果表明：CdSe量子点经过表面修饰后，两相电子注入机制———热电子和冷电子注入得以被证实，即：电子能分别从CdSe量子点导带中高的振动能级和导带底转移到TiO2的导带。该机制详细描绘了电子在纳米界面间转移的图景。进一步研究发现：热电子注入的电子耦合强度（3．6±0．1 meV）比弛豫后的基态电子注入高两个数量级，基于Marcus理论，伴随着0．083 eV的重组能，冷电子注入的耦合强度值为～50μeV。
이용초쾌광보기술계통연구료재정알포과적CdSe양자점민화적TiO2납미정박막기시시각계면간전자전이동역학。여지전적보도불동，해실험결과표명：CdSe양자점경과표면수식후，량상전자주입궤제———열전자화랭전자주입득이피증실，즉：전자능분별종CdSe양자점도대중고적진동능급화도대저전이도TiO2적도대。해궤제상세묘회료전자재납미계면간전이적도경。진일보연구발현：열전자주입적전자우합강도（3．6±0．1 meV）비이예후적기태전자주입고량개수량급，기우Marcus이론，반수착0．083 eV적중조능，랭전자주입적우합강도치위～50μeV。
In this paper, we have investigated the initial interfacial electron transfer dynamics in butylamine-capped CdSe quantum dot( QD)-sensitized nanocrystalline TiO2 films by ultrafast spectroscopy.Different with previous reports, the experiment results indicate that after surface modification of CdSe QDs, a two-phase electron injection mechanism ( hot and cold electron injection ) is validated, namely, electrons transfer from high vibration energy levels in conduction band and conduction band bottom of CdSe quantum dots into con-duction band of TiO2 , respectively.This mechanism depicts a picture on the detailed charge transfer processes at the nano interfaces.We further find that the electron coupling strength (3.6 ±0.1 meV) of hot electron in-jection is two orders of magnitude larger than that of relaxed ground-state electron injection, which gives a val-ue of ~50 μeV accompanied with reorganization energy 0.083 eV on the basis of Marcus theory.