Simple Yet Efficient Chemically Deposited AG Rear Side Metallization on ITO for High-Efficiency c-Si Solar Cells

A simple process for preparation of full-area Ag rear side contacts on indium tin oxide (ITO) coated heterojunction technology (HJT) Si solar cells was developed. It employs the well known Tollen's reagent to chemically deposit Ag. Investigations of the microstructure revealed that dense Ag layers without pores are formed. Compared with evaporated Ag the optical and electrical performance of HJT solar cells is practically the same if edge shunts can be avoided by thorough application of a polymer ink all around the edge before chemical Ag deposition. Hence, expensive high-vacuum deposition systems can be replaced. The process is well suited for lab R & D and could also find application in production when combined with smart wire connection technology.