新型铁基光伏材料性能研究与器件探索

Ultra-large-scale application of solar cells is prohibited by the problem of high cost. The development of novel low-cost, highly absorptive photovoltaic materials, will significantly reduce the need of raw material and cost. This project is aimed to develop novel low-cost Fe-based photovoltaic materials with great structural stability and excellent charge transport properties, by surface modification and structural tailoring the highly absorptive FeS2. The main contents are as follows: (1) FeS2 performance enhancement by doping and surface modification. Introducing strong chemical bond in FeS2 surface to bind S and modifying suface by high-S chemical potential layer, to stabilize the S-sublattice, overcoming the effect of Fermi level pinning. (2) FeS2 lattice structural tailoring. Maintain the FeS2 skeleton crystal structure and electronic structure near Fermi level, directly introducing Al, Ga, Si and Ge, which can be strongly bonded to S, into the lattice of FeS2, forming naturally coexisted structural units, to avoid the sub-lattice instability. (3) Fabrication of Fe-based thin films and devices. Optimize the performance of Fe-based photovoltaic materials, deposit thin films, and fabricate devices, refering to the typical compound thin film photovoltaic device structure.

太阳电池的大规模应用还面临成本过高的问题，开发新型廉价光伏材料，提高光吸收系数，将大幅减少材料用量和降低成本。本项目围绕光吸收系数极高的FeS2进行改性研究、结构剪裁和光电性能优化，在保持高吸光特性的同时，开发出结构稳定、电荷输运性能优异的新型铁基光伏材料。主要研究内容如下：（1）FeS2掺杂改性与表面修饰。利用表面强键的绑定作用和高S化学势修饰层的抑制作用，稳定FeS2表面的S亚晶格，克服费米能级钉扎效应。（2）FeS2晶格结构剪裁。保持FeS2骨架结构和费米面附件电子结构基本不变，在FeS2的晶格中直接引入与S强力键合的元素Al, Ga, Si, Ge等，形成自然共存的结构单元，避免材料的亚晶格失稳。（3）铁基光伏材料的薄膜制备与器件探索。优选性能优异的铁基光伏材料，进行薄膜化制备研究，并参考典型的化合物薄膜光伏器件结构，探索铁基光伏器件的集成。

太阳电池的大规模应用还面临成本过高的问题，开发新型廉价光伏材料，提高光吸收系数，将大幅减少材料用量和降低成本。本项目围绕光吸收系数极高的铁基光伏材料进行改性研究、结构剪裁和光电性能优化，在保持高吸光特性的同时，开发出结构稳定、电荷输运性能优异的新型铁基光伏材料。主要研究成果如下：（1）开发了一系列新型铁基光伏材料。（2）开发了新型低成本非真空光伏薄膜制备技术，并实现了8%以上的光电转换效率。（3）开发了新型钙钛矿光伏薄膜与器件的制备技术，实现了13%以上的光电转换效率。