用于高效钙钛矿太阳电池的新型有机电荷传输材料

Perovskite solar cell is the hot topic and research frontier of photovoltaic field. However, to further advance it has been suffered from the lack of effective and mild-processing charge transport materials that can match well with the emerging perovskite absorbers. For instance, the most frequently used transport materials require either harsh temperature-annealing (for mesoporous TiO2) or instable doping (for spiro-OMeTAD). Herein, we propose to develop dopant-free and solution-processable transport materials basing on the planer, rigid, and fully conjugated polymeric and molecular backbone. For instance, hole transport materials (HTMs) will be made with the phenyl and thiophene moieties based co-polymers, and truxene small molecule. In addition, electron transport materials (ETMs) containing naphthalene-1,4,5,8-tetracarboxylate, and fullerene moieties will be designed and synthesized. We will first engineer those molecular backbones to enhance the charge transport capabilities, and further incorporate heteroatom containing functional groups to tune the energy level, absorption, and surface energy of new materials. So that new HTMs and ETMs are expected to simultaneously exhibit multi-functionalities, such as the guidance of crystalline perovskite growth, and passivation of defeats. Through investigating the correlation between molecular architecture, material properties and the device parameters, we target to explore the new molecular strategy to access efficient materials that enable effective organic-inorganic hybrid perovskite solar cell over 20% power conversion efficiency.

钙钛矿太阳电池是光电领域研究热点和前沿，但目前使用的电荷传输材料要么无法低温加工（如介孔TiO2）要么需掺杂（如spiro-OMeTAD）导致器件重复性和稳定性变差，限制其实际应用。据此，本项目提出了构筑可溶液加工、免掺杂的有机电荷传输材料的分子设计新策略，即引入平面、刚性、全共轭的分子骨架，设计合成以苯环和噻吩交替共轭高分子为主链和三聚茚（Truxene）为内核的空穴传输层材料，以及基于萘四甲酸酯的高分子和自掺杂的富勒烯类电子传输层材料，以在免掺杂下获得高迁移率和导电率，并诱导钙钛矿薄膜结晶生长，填补表面缺陷，实现电荷的高效提取和传输。系统研究传输材料的迁移率、能级、吸光、表面能与分子结构的内在关系，初步探明传输材料对钙钛矿太阳电池电荷产生、传输和收集等光伏过程的影响规律，获得效率大于20%的低温、全溶液加工的免掺杂钙钛矿太阳电池原型器件，为促进钙钛矿电池发展提供新材料和新手段。

太阳能光电转换是国家清洁能源重要发展战略，探索发展新型光伏技术和应用具有积极意义。本项目中，我们提出发展了酸碱作用调谐钙钛矿界面的分子策略，设计合成了包含新型共轭基元的免掺杂电子和空穴传输分子，实现了钙钛矿与有机传输材料层之间的高效电荷提取和输运，成功获得了高效、稳定的钙钛矿太阳电池，包括小面积原型器件和涂布的大面积组件。发表基金标注论文36篇，其中影响因子超过10的论文17篇，授权发明专利2项。成果受到同行拓展应用，在新兴的建筑集成光伏领域具有应用前景，并取得具有一定国际影响力，项目负责人连续入选英国皇家化学学会能源和可持续性期刊Top 1%高被引中国作者（2019、2020 ），和科睿唯安发布的全球高被引科学家（2019、2020）。