基于硫化物纳米电极的高效CdSe/CuInS2量子点太阳电池研究

Aiming at the important science problems and key technology issues on the traditional quantum dot solar cells (QDSSCs) made from low fill factor and photovoltage, mismatch of energy level on the counter electrode (CE), electrolyte and QDs, and not green, innovative researches on design preparation and application technology for the key materials including of sulfides CEs and QDs sensitizers are carried out. ① Constructing the dense layer for substrates, reducing the dark current and improving the fill factor of the device; ② preparation p or n type CuInS2 (CIS) QDs with low toxicity, provided the core/shell CIS/ZnS QDs for restraining the recombination reaction of photogenerated electrons occurred at the defect state, leading to the enhancement of the photovoltage and photocurrent; ③ introduction the transition metal sulfides CEs (NiS, CoS, MoS2, VS2), and establishment optimum energy level on the CE-electrolyte-QDs, further improving the efficiency of the solar cells. Through the materials’ design synthesis, property measurement, structure characterization, device fabrication and performance evaluation, the principle and mechanism for photoinduced charge carrier production, evolvement and transportation are clarified, the relationship between the microstructure of each component with photovoltaic properties and long-term stability for the cells is elucidated, the key issues for materials design synthesis and device fabrication are solved. Thus，the novel quantum dot solar cell with power conversion efficiency over 10% is achieved and provide technology support for new energy development.

针对传统量子点太阳电池填充因子偏低、光电压较小、对电极和电解质、量子点能级不匹配、不环保等科学问题，开展硫化物对电极材料和低毒量子点敏化剂的设计和可控制备和应用技术创新性研究。①构建衬底致密层，减少暗电流，提高电池填充因子；②制备p型或n型低毒CuInS2(CIS)量子点，构筑CIS/ZnS核/壳结构抑制光生电子发生在缺陷态的复合反应，提高电池光电压和光电流；③引入与CIS能级匹配的过渡金属硫化物（NiS、CoS、MoS2、VS2）杂化对电极，建立对电极-电解质-量子点最佳能级匹配，进一步提高电池效率。通过材料的设计合成、性能测定、结构表征、器件组装和效能评价，厘清光生载流子产生、演化、输运机理和调控机制，揭示电池各基元的微观结构与宏观光伏性能及长程稳定性之间的关系，解决材料设计合成和器件组装的关键问题，提供光电转化效率超过10％的新型量子点太阳电池，为新能源发展提供技术支撑。

我们采用水热法原位合成出过渡金属氧化物、硫化物和多元合金化合物及其碳材复合材料作为太阳能电池的对电极催化材料。通过广泛的电化学和光电化学表征测试，研究合成温度梯度、时间和碳材的含量与其导电催化性能之间的关系，揭示了工艺条件对所制备的过渡金属纳米电极材料的晶体结构、晶体质量、形貌、晶粒大小、催化性能等的影响规律。通过光电性能测试表征，揭示纳米对电极与太阳电池宏观光伏性能的关系。为了进一步提高DSSC的稳定性，我们研制了双功能导电凝胶电解质，用于染料敏化太阳能电池（DSSC），显著地改善了电化学和光电化学性能。这些新型电解质为电子传输提供了三维网状结构，与I−/I3−液体电解质系统有相似的传导机制。在上述研究基础之上，我们采用热注入法制备不同粒径尺寸和带隙可调的CuInS2量子点材料，并通过ZnS表面包覆钝化层提高量子点的荧光效率和抗光褪色能力，进一步提高量子点的稳定性。基于过渡金属化合物纳米复合电极和凝胶电解质组装成的CuInS2/ZnS量子点太阳能电池具有良好的稳定性能。为了扩展太阳能电池的实际应用，我们成功制备了单根柔性纤维染料敏化太阳能电池，在标准太阳光照射下获得6.33%转换效率。另外，积极探索CuInS2量子点可穿戴柔性有机太阳能电池和可穿戴柔性染料敏化太阳能电池。