“…Various non‐vacuum methods, which are suitable for commercialization, including sol–gel methods, [27,28] spin coating, [29] the hydrazine‐slurry method, [12] and electrodeposition, [1,5,15] have been used to fabricate CZTSSe‐based thin‐film solar cells. Among these potential methods, single‐step electrodeposition (co‐electrodeposition) was adopted in the current study because of its technical advantages, including eco‐friendliness, low capital cost, scalability for large‐area deposition, and high precursor use [5,15,30–34] . However, this method often causes morphological problems, such as the formation of pinholes, which act as shunt pathways leading to the poor device performances.…”