Thin films formed by complexation of oppositely charged polyelectrolytes have significant potential in applications such as separation membranes, biocompatible or anticorrosion coatings, and drug delivery systems. While layer-by-layer deposition is a reliable method for producing conformal films, this multi-step process limits scalability. In this study, we functionalize polymers with photoactive protecting and crosslinking groups, allowing a one-step approach for preparing polyelectrolyte complex (PEC) films. To achieve this goal, we introduced