Recently, silver (Ag) substitution for copper (Cu) into Cu(In,Ga)Se₂ (CIGS) films has attracted widespread attention due to the lower synthesis temperature and the enlarge band gap. In this paper, SCAPS simulation is employed to investigate the influence of Ag doped CIGS absorber layer on the lattice defect and band gap gradient. First, the impact of the [Ga]/([In] + [Ga]) (GGI) and [Ag]/([Ag] + [Cu]) (AAC) on the defect concentrations is calculated systematically. It is demonstrate that the compression (GGI > 0.25) is more likely to cause the tetragonal distortion compared with the tension (GGI < 0.25) on the unit cell. And appropriate substitution of Cu with Ag can reduce the defect concentrations. Further investigations on the variation of the lattice structure indicate the ideal band gap can be enlarged to the range of about 1.20–1.29 eV by silver. With the ideal lattice structure, the efficiency of solar cells has a relative increase of about 48 % compared with that of the reference solar cell. This study offers a new sight for the incorporation of Ag into CIGS films from the perspective of lattice structure, which should be further improve device performance of CIGS solar cells at low temperature deposition process.

最近，银 (Ag) 将铜 (Cu) 置换为 Cu(In,Ga)Se ₂（CIGS）薄膜由于较低的合成温度和较大的带隙而受到广泛关注。在本文中，SCAPS 模拟被用来研究 Ag 掺杂的 CIGS 吸收层对晶格缺陷和带隙梯度的影响。首先，系统地计算了 [Ga]/([In] + [Ga]) (GGI) 和 [Ag]/([Ag] + [Cu]) (AAC) 对缺陷浓度的影响。结果表明，与张力（GGI < 0.25）相比，压缩（GGI > 0.25）更可能导致晶胞上的四边形畸变。用Ag适当取代Cu可以降低缺陷浓度。对晶格结构变化的进一步研究表明，银可以将理想带隙扩大到约 1.20-1.29 eV 的范围。具有理想的晶格结构，与参考太阳能电池相比，太阳能电池的效率相对提高了约48%。该研究从晶格结构的角度为将Ag掺入CIGS薄膜提供了新的视角，这将进一步提高CIGS太阳能电池在低温沉积过程中的器件性能。