本文总结了Cu(In, Ga)Se₂ (CIGS) 电池中掺杂碱金属的发展历史和一些重要成果，综述了碱金属掺杂方式对CIGS 吸收层及器件性能的影响。通过分析由(NaF+KF)-PDT 导致的CIGS 表面结构及电学性能的改变，我们提出并解释了如下几个问题：①在低温沉积CIGS 薄膜过程中，Na 促进了CuInSe₂的优先形成，排挤Ga 向Mo 衬底扩散，造成CIGS 薄膜的分层现象；② Na 原子钝化CIGS 晶界及表面缺陷从而提高空穴载流子浓度的相关机制；③过渡层减薄提高了短路电流（J_SC）而不产生开路电压（V_OC）损失，这不仅归因于化学浴沉积初期过渡层较好的包覆性，还在于受主缺陷$V_{{\mathrm{Cu}}^{-}}$ 转型为施主缺陷${\mathrm{Cd}}_{\mathrm{Cu}}^{+}$时密度的增加，强化了同质浅埋结；④ (NaF+KF)-PDT 使CIGS 吸收层表面价带降低，进一步抑制了CIGS 吸收层和过渡层界面的复合，是提高电池开路电压与填充因子的重要原因。

This paper reviews the development history of alkali element doping on Cu(In,Ga)Se₂ (CIGS) solar cells and summarizes important achievements that have been made in this field. The influences of incorporation strategies on CIGS absorbers and device performances are also reviewed. By analyzing CIGS surface structure and electronic property variation induced by alkali fluoride (NaF and KF) post-deposition treatment (PDT), we discuss and interpret the following issues: ① The delamination of CIGS thin films induced by Na incorporation facilitates CuInSe₂ formation and inhibits Ga during low-temperature co-evaporation processes. ② The mechanisms of carrier density increase due to defect passivation by Na at grain boundaries and the surface. ③ A thinner buffer layer improves the short-circuit current without open-circuit voltage loss. This is attributed not only to better buffer layer coverage in the early stage of the chemical bath deposition process, but also to higher donor defect (${\mathrm{Cd}}_{\mathrm{Cu}}^{+}$) density, which is transferred from the acceptor defect (${\mathrm{V}}_{\mathrm{Cu}}^{-}$) and strengthens the buried homojunction. ④ The KF-PDT-induced lower valence band maximum at the absorber surface reduces the recombination at the absorber/buffer interface, which improves the open-circuit voltage and the fill factor of solar cells.