Smooth Cu electrodeposition for Cu(In, Ga)Se2 thin-film solar cells: Dendritic clusters elimination by Ag buffer layer

Smooth and compact Cu(In, Ga)Se-2 (CIGSe) thin film is critical to prepare high-quality solar cells. However, the dendritic morphology of Cu tends to form on Mo leading to a nonuniform Cu distribution during the electrodeposition process, which affects the uniformity of CIGSe and device performance. In this work, Ag was used as the underlying buffer layer and Cu was electrodeposited on Ag film instead of Mo film. By adjusting deposition parameters, smooth and compact Ag layer was obtained on the Mo surface. With the Ag buffer layer, the dendritic Cu on Mo was successfully eliminated. The electrodeposited Ag/Cu/In/Ga metal precursors were annealed in Se-containing atmosphere at 450 degrees C similar to 550 degrees C for 15min to prepare (Ag, Cu)(In, Ga)Se-2 (ACIGSe) absorbers. Compared with the CIGSe absorber, the crystallinity of the ACIGSe absorber was improved. The V-OC, J(SC), FF and efficiency of ACIGSe solar cells were improved compared with CIGSe solar cells. Ultimately, an 11.73% efficiency of ACIGSe thin-film solar cells was obtained. (C) 2022 The Authors. Published by Elsevier Ltd.

Automated summary

In this study, an Ag buffer layer was used to eliminate the nonuniform distribution of Cu on Mo, resulting in improved crystallinity and performance of ACIGSe absorber and solar cells.