石墨相氮化碳/量子点异质结的可控制备及其光伏性能研究

共轭聚合物/量子点太阳能电池兼具聚合物柔性、重量轻的特点和量子点带隙可调、多激子效应的特点而具有巨大的发展潜力，成为研究热点。本项目拟设计和制备能级匹配的石墨相氮化碳共轭聚合物/量子点异质结太阳能电池材料，并研究其光伏特性。石墨相氮化碳具有半导体结构，价格低廉，易进行化学修饰，化学与热稳定性高等特性，采用石墨相氮化碳作为聚合物电池新型受体，与无机半导体量子点直接键合形成异质结，既可使量子点不团聚，又可以促进光生电子-空穴的分离，减少他们的复合，从而有效提高光电转换效率，同时可以克服量子点电池的不稳定性。本项目将系统研究制备方法、条件对异质结结构的影响，探讨异质结形成机理，实现g-C3N4/量子点异质结微结构的可控制备。研究太阳能电池光电子的产生、分离、传输以及光电转换机理，揭示异质结电池的光伏特性与微结构的关系，建立相应的光电导模型。为潜在的高效低廉光伏电池的应用开发提供理论和实验基础。

Polymer/inorganic semiconducting quantum dots take advantage of the rich optoelectronic properties of polymers as well as the size and shape dependent band gaps of quantum dots semiconducting nanomaterials. As a result, polymer/inorganic semiconducting quantum dots exhibit high carrier mobilities as well as an increase in the range of light absorption. Here,we design and controllable synthesize the heterojunction of graphitic carbon nitride / Quantum dots and study theirs the photovoltaic performance as active layer.Polymeric carbon nitride is a typical semiconductor with a band gap of 2.7 eV, as revealed by theoretical calculations. Properties such as a low price, amenability to mass preparation and chemical modification, and especially, contrary to many other organic semiconductors, a high thermal and chemical stability against oxidation stable in air up to 550 o C, make carbon nitride solids a very promising candidate for solar energy converting systems, such as photoelectrochemical cells, which are not yet available. The processing condition of forming heterojunction was optimized and its reaction mechanism was also studied. The photovoltaic performance of solar cell is strongly dependent on the light harvesting, energy levels of materials, the morphology of heterojunction films, the g- C3N4 structure, the size of QDs, and so on. The impact of the above factors such as device structure, morphology of heterojunction on photovoltaic performance is discussing. Thus, the heterojunctions solar cells which have a lower cost and high efficiency should be obtained.