基于黄铜矿结构化合物作为太阳能吸收材料的改良-中间带的理论设计

As a kind of absorbers for the intermediate band solar cell, Cu-based chalcopyrite compounds have been paid much attention by material scientists in recent years. In this proposal, we attempt to study the changes on the electronic structures, intermediate bands, optical properties etc. of the systems by using the first-principles calculations, which are derived from the I-III-VI2, II-IV-V2-based chalcopyrite compounds with suitable band gaps doped with different kinds of dopants. We try to investigate the influence on the optical properties of intermediate band absorbers originally from the difference of the host and dopant on the electronic structure level and find out corresponding microscopic clues. We will discuss the stabilities on the crystal structures and electronic structures of the interesting systems and then screen the promising intermediate band absorbers. Moreover, we try to grasp the rules for adjusting and optimizing the property by codoping methods. Finally, we supply the research plan on the intermediate band absorber at the electronic structure level, which is close to the actual experimental research.

Cu基黄铜矿结构化合物是近年来受到广泛关注的一类中间带太阳能吸收材料。本项目采用第一性原理计算方法，以禁带宽度适宜的I-III-VI2, II-IV-V2族黄铜矿结构化合物作为母体材料，研究掺入不同种类杂质后材料的电子结构、杂质中间带、光学特性等的变化，探寻母体材料和掺杂元素在电子结构层次的异同对中间带太阳能吸收材料光学特性的影响，找出相应的物理化学规律。对所关注的研究体系开展晶体结构和电子结构稳定性的探讨，筛选出具有潜力中间带吸收材料，并进一步掌握共掺杂调节及优化材料性能的物理规律。最终，从电子结构层次获得贴近实验的中间带太阳能吸收材料的研究方案。

探寻克服单结太阳能电池Shockley-Queisser理论极限的途径是太阳能吸收材料研究的重要领域之一，中间带太阳能吸收材料能够通过禁带中半满的中间带在单一材料中实现价带到导带，价带到中间带，中间带到导带的三光子吸收过程，而被视为具有前景的高效太阳能吸收材料。在本项目中，通过第一性原理计算研究，开展了主要基于黄铜矿结构化合物，通过重掺杂形成半满中间带的研究工作。理论预测了一系列具有前景的中间带太阳能吸收材料，总结了中间带形成及能量排布的微观规律，提出了一种将中间带与叠层方法相结合克服Shockley-Queisser理论极限的方案。该项目的完成能推动中间带太阳能吸收材料的研究工作，为设计出高效的太阳能吸收材料提供了方案。