This study presents a systematic investigation into the morphological evolution of spray-coated organic solar cells (OSCs) during in-situ thermal annealing, focusing on the role of additive-induced aggregation in the transition from disordered to ordered structures. Through the application of GISAXS and GIWAXS techniques, the phase transition and structural ordering processes within the active layer are examined in detail. The research aims to elucidate the interplay between morphology modulation and device performance, ultimately clarifying the structure–property relationships that govern the efficiency of additive-processed OSCs fabricated via ultrasonic spray deposition.