基于碳纳米管薄膜和钙钛矿型材料的高效、红外可透太阳电池的研究

The use of polymer-based hole-conduction layer and precious metal electrodes in perovskite solar cells has greatly increased their cost. This proposal is to employ carbon nanotube (CNT) film, which is highly light-transparent, conductive and cost-competitive, as both hole-conduction layer and electrode in perovskite solar cells. By configuring CNT film with organolead halide perovskites, heterojunction solar cells which are absorptive to ultraviolet and visible light but transparent to infrared will be fabricated. To satisfy the requirements on materials, process parameters are to be hereby optimized to regulate the basic properties of CNT films (transmittance, conductivity, work function, etc.) and perovskite materials (band gap, carrier concentration, conductivity, etc.) accordingly. Meanwhile, the interface status between CNT films and perovskite materials will be further explored to reveal the work mechanism and enhance the conversion efficiency of the solar cells. Beyond this, these infrared-transparent perovskite solar cells and Cu(In,Ga)Se2 solar cells are to be assembled in tandem structure. The thickness of absorption layer in perovskite solar cells will be regulated, in order to realize performance matching and effective assembly of these two solar cells. Therefore perovskite solar cells with extended range of spectral response, enhanced efficiency and reduced cost are expected.

在钙钛矿型太阳电池中，聚合物基空穴传导层和贵金属电极材料的使用，大幅度提高了电池的材料成本。本项目拟以具有高透光性、导电性的碳纳米管薄膜作为空穴传导层和电极材料，直接与钙钛矿型有机铅卤化合物构成异质结，从而获得对紫外和可见光吸收、对红外光透过的太阳电池。根据高效钙钛矿型太阳电池对材料的要求，通过工艺参数优化，分别对碳纳米管薄膜的透光性、导电性、功函数和有机铅卤化合物的禁带宽度、载流子浓度、电导率等重要性质进行调控，并改善两者间的界面状态，提高电池的光电转换效率并揭示其工作机理。在此基础上，将红外可透的钙钛矿型太阳电池与铜铟镓硒太阳电池进行叠层组装，通过调控钙钛矿型太阳电池吸收层的厚度，实现两电池在性能上的匹配并有效组装，扩展电池整体的光谱响应范围，为高效、低成本的钙钛矿型太阳电池的实际应用奠定基础。

开发高性能的碳纳米材料和钙钛矿材料，对解决日益紧张的能源、环境问题具有重要的科学意义和实用价值。本项目开发一种先退火后电抛光处理铜箔，获得极光滑金属基底的有效方法，研究了CVD系统中水分子分压对石墨烯质量的影响。通过优化参数，所制备的石墨烯薄膜具有更低的成核密度、缺陷密度和更高的电输运性能，这将为石墨烯及其他二维材料的制备提供新的思路；依托本项目制备的高质量石墨烯薄膜，已进入卫星搭载的实验研究阶段。通过向钙钛矿前躯体中引入氯元素，钙钛矿薄膜的平均晶粒尺寸由增大至353nm，形成贯通薄膜厚度方向的钙钛矿大晶粒，从而将钙钛矿太阳能电池的效率提升至17.0%。通过对钙钛矿前驱体的高温退火处理，可快速将其制备成大晶粒的柱状晶钙钛矿薄膜，也获得了大于16%的光电转换效率。将碳纳米管薄膜作为窗口层和空穴收集层，应用于钙钛矿纤维太阳能电池，钙钛矿中氯元素的掺杂对提高电池的效率和稳定性起到了重要的作用。基于项目开发的高性能碳纳米管材料，结合航天的特点和需求，开发了超黑碳纳米管薄膜，光吸收率达99%，以水蒸发净水为示例验证了其光热转换能力，净水效率达84%；开发了超疏水碳纳米管仿生薄膜，接触角达152°，滚动角仅为2°，薄膜具有优异的水面承载能力，可达627 g/g；结合碳纳米管薄膜优异的X射线透过率和导电性，制备了碳纳米管/硅异质结X射线探测器，具有良好的X射线响应特性。依托本项目所开展的这些研究，将为碳纳米材料、钙钛矿材料在能源和航天领域的应用提供重要的参考价值。