钙钛矿CH3NH3PbI3与PbS量子点间的电荷转移动力学研究

项目名称： 钙钛矿CH3NH3PbI3与PbS量子点间的电荷转移动力学研究

项目编号： No.21503221

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 王俊慧

作者单位： 中国科学院大连化学物理研究所

项目金额： 21万元

中文摘要： 钙钛矿太阳能电池因其较高的能量转换效率（PCEs，最高达19.3%）而引起了极大的关注，但一直存在着钙钛矿CH3NH3PbI3吸收带仅局限于1.57 eV的问题。因此，与吸收近红外光的纳米颗粒共敏化，是进一步提高钙钛矿材料光谱响应的有效方法之一。目前，对近红外量子点（QDs）-钙钛矿共敏化太阳能电池的研究较为广泛，但其研究的核心问题都是如何提高电池的PCEs，而QDs是如何在钙钛矿太阳能电池中发挥作用的动力学机理则从未涉及。本项目将以PbS QDs和钙钛矿CH3NH3PbI3分子为研究对象，利用空间分辨的荧光成像和时间分辨的瞬态吸收系统，实现对PbS QDs和CH3NH3PbI3间电荷转移动力学及其动力学机理的系统研究，建立材料微观结构、物理尺寸与电荷转移速率的相互关联，探索分子间的电荷转移作用机理，为建立高效的CH3NH3PbI3-QDs共敏太阳能电池体系提供材料表征和动力学基础。

中文关键词： 量子点；钙钛矿；荧光成像；瞬态吸收；电荷转移动力学

英文摘要： Solar cells based on perovskite materials have attracted great attention due to their higher power conversion efficiencies (PCEs, up to 19.3%). However, the absorption onset of perovskite CH3NH3PbI3 is limited to 1.57 eV. Therefore, an effective approach to further increase the spectral response of these materials is co-sensitization with near IR absorbing nanoparticles. At present, near IR quantum dots (QDs)-perovskite co-sensitization solar cells are one of the most intensively investigated systems. At the heart of above work is how to improve their PCEs, but the dynamics mechanism of how the QDs plays a role in perovskite solar cells has never been reported. Our research, taking the PbS QDs and perovskite CH3NH3PbI3 as an example system, will realize a systematic research on the charge transfer dynamics and its dynamic mechanism between PbS QDs and CH3NH3PbI3 by spatial-resolved fluorescence imaging and time-resolved transient absorption. This will build the relationships between the microstructure- or size-charge transfer dynamics and seek to determine how variations between different nanoparticles, different sites and surface characters affect charge transfer. Our research will provide significant insights for the development of highly efficient CH3NH3PbI3-QDs co-sensitization solar cells.

英文关键词： quantum dots;perovskite;fluorescence imaging;transient absorption; charge transfer dynamics