耦合量子点薄膜中光致界面电荷转移

Photo-induced charge transfer dynamics at interfaces in coupled quantum dot films

为了更好地了解量子点光伏器件的工作过程,从而为设计高效量子点光伏器件提供依据,研究了CdSe耦合量子点薄膜在不同时间尺度的界面电荷转移动力学特性。通过瞬态光电流(TOF)研究了量子点与电极之间的界面电荷转移及随后发生的载流子复合过程,结果表明,后者的时间尺度约在120ns左右;然后对比单双层量子点光伏器件TOF信号,结果表明在双层量子点光伏器件中存在不同尺寸量子点之间的界面电荷转移过程;最后采用时间分辨荧光光谱手段研究了量子点与受体之间的界面电荷转移过程,结果表明该过程发生在几十ps的时间尺度。

Focusing on photovoltaic device working processes, as to design higher efficiency quantum dot photovoltaic device, charge transfer dynamics at interface in quantum dot films at different time scales are studied. The results of transient photocurrent （Time of Flight/TOF） indicate charge transfer at interfaces between quantum dots and electrodes, then charge carriers recombination occurs, the time scale for later is about 120 ns. Furthermore, by comparing single and two sizes quantum dot plotovoltaic devices＇ TOF signals, we arrive at a conclusion that the contribution of interface charge transfer between different sizes quantum dots. In the end, time-resolved fluorescence spectrum is used to study interface charge transfer between quantum dots and acceptors, the results reveal that the processes occur at tens of ps.