基于多级纳米异质结构量子点敏化光阳极和铜锌锡硫硒（CZTSSe）光阴极的叠层太阳能电池材料与器件研究

Fabrication of high-efficiency tandem solar cell via low-cost solution process has long been considered as an important topic in the area of solar energy photo-to-electric conversion. In this project, we will focus on a novel tandem solar cell based on quantum dot (QD) sensitized photoanode and CZTSSe heterojunction photocathode, and will investigate issues related to the fabrication of device and optimization of device performance in the viewpoint of materials science. In the aspect of photoanode, we will conduct research on the preparation and interface modulation of a kind of CdSe and CdS QDs co-sensitized rutile TiO2 nanowire array coated with anatase TiO2 nanoparticles, and investigate how the multi-nanoheterojunction influences the charge separation and charge collection performance of photoanode under the excitation of visible light. In the aspect of photocathode, we will explore the method to prepare high quality CZTSSe film and construct CZTSSe/CdS/ heterojunction via solution process, and the method to prepare highly active CoS electrocatalyst on CZTSSe/CdS film with high light transmission, and investigate how to achieve high solar energy conversion efficiency with the photocathode under the excitation of near-infrared light. Finally, we will assemble tandem solar cell with the QD-sensitized photoanode, CZTSSe/CdS/CoS photocathode, and sulfide/ polysulfide electrolyte based on the current match principle, and investigate how to achieve high solar energy conversion efficiency with the tandem cell. The project will provide scientific reference to the fabrication of high- efficiency tandem solar cells via solution process.

以溶液沉积等低成本方法制备高效率叠层太阳能电池是太阳能光电转换领域的重要课题。本项目聚焦一种基于量子点敏化光阳极和CZTSSe光阴极的新型叠层太阳能电池，研究器件制备与性能优化涉及的材料科学问题。在光阳极方面，研究一种CdSe和CdS量子点共敏化锐钛矿TiO2纳米粒子/金红石TiO2纳米线复合阵列结构的制备与界面调控，利用多级纳米异质结构增强光阳极电荷分离和输运性质获得对太阳光谱可见光波段的高效率光电转换。在光阴极方面，研究用溶液沉积方法制备高质量CZTSSe薄膜及CZTSSe/CdS异质结，和在薄膜表面制备高活性和光透过性CoS电催化剂的方法，利用异质结内建电场增强CZTSSe薄膜电荷分离实现光阴极对太阳光谱近红外波段的高效利用。基于电流匹配原则组合光阳极、光阴极和多硫化物电解质制备叠层太阳能电池，研究实现高效率太阳能转换的途径，为溶液沉积制备高效率叠层太阳能电池提供科学依据。

以溶液沉积等低成本方法制备高效率叠层太阳能电池是太阳能光电转换领域的前沿和热点。本项目以量子点敏化叠层太阳能电池为研究对象，针对量子点敏化纳米线光阳极、铜锌锡硫类光阴极、以及叠层器件的制备与优化开展了系列研究工作。光阳极方面：深入研究了晶种层及反应参数对TiO2纳米线阵列生长的影响规律，获得了TiO2纳米线阵列及分级异质结构的可控制备技术；探索了溶胶-凝胶法制备CdS界面层的条件，得到了最佳化学计量比CdS量子点敏化太阳能电池界面层；深入研究了不同表界面处理对CdSe量子点敏化光阳极光电化学性能的影响规律。光阴极方面：利用溶胶-凝胶结合快速退火法制备铜锌锡硫类Cu2ZnSnS4、Cu2CoSnS4、Cu2NiSnS4和Cu2ZnSn(S,Se)4薄膜，发展了化学浴沉积、喷雾热解-后硫化等工艺制备Cu2S、CoS、Co3O4/Co3S4等电催化剂，构造了Cu2ZnSnS4/Cu2S等异质结型光阴极，研究了结构组成及界面特性对其光电化学性能的影响。叠层电池器件方面，探索了CdS量子点敏化光阳极与CZTS光阴极叠层光电化学太阳能电池器件、CdS/ CdSe量子点共敏化光阳极与 Cu2S/ TiO2/CdS/CZTSe复合异质结构光阴极叠层光电化学太阳能电池器件、以及自驱动太阳能产氢叠层光电化学水分解系统的制备技术并进行性能优化，获得了3.13%的叠层太阳能电池光电转换效率。本项目在TiO2纳米线阵列的晶种层调控生长、致密CdS界面层提升量子点敏化光阳极性能、界面SnO2层调控CZTS晶粒生长、喷雾热解-后硫化法制备高性能电催化剂等方面取得了较为重要的研究结果，对于新型纳米线太阳能电池的相关研究具有一定的参考价值。