A solar cell is a photovoltaic device that converts solar radiation energy to electrical energy, which plays a leading role in alleviating global energy shortages and decreasing air pollution levels typical of conventional fossil fuels. To render solar cells more efficient, high visible-light absorption rates and excellent carrier transport properties are required to generate high carrier levels and high output voltage. Hence, the core material, i.e., the absorption layer, should have an appropriate direct band gap and be effectively doped by both p- and n-types with minimal carrier traps and recombination centers. Consequently, defect properties of absorbers are critical in determining solar cell efficiency. In this work, we review recent first-principles studies of defect properties and engineering in four representative thin-film solar cells, namely CdTe, Cu(In,Ga)Se₂, Cu₂ZnSnS₄, and halide perovskites. The focal points include basic electronic and defect properties, existing problems, and possible solutions in engineering defect properties of those materials to optimize solar cell efficiency.

太阳能电池是将太阳辐射能转换为电能的光伏装置，在缓解全球能源短缺和降低传统化石燃料典型的空气污染水平方面发挥着主导作用。为了提高太阳能电池的效率，需要高可见光吸收率和出色的载流子传输特性以产生高载流子能级和高输出电压。因此，核心材料，即吸收层，应具有适当的直接带隙，并以最小的载流子陷阱和复合中心有效地被p型和n型掺杂。因此，吸收体的缺陷特性对于确定太阳能电池效率至关重要。在这项工作中，我们回顾了最近对四个代表性薄膜太阳能电池的缺陷特性和工程学的第一性原理研究，₂，Cu ₂ ZnSnS ₄和卤化物钙钛矿。焦点包括基本的电子和缺陷特性，存在的问题以及那些材料的工程缺陷特性以优化太阳能电池效率的可能解决方案。