Annealing-free perovskite films by EDOT-assisted anti-solvent strategy for flexible indoor and outdoor photovoltaics

To promote the commercialization of perovskite photovoltaics, the development of annealing-free techniques is one of effective strategies to lowering the whole manufacture cost. Unfortunately, annealing-free perovskite films are always accompanying with unsatisfactory crystallization, which would cause defect generation and adverse carrier nonradiative recombination. Herein, we chose triple-cation perovskite and introduce 3,4-ethoxylene dioxy thiophene (EDOT) into anti-slvent to realize annealing-free perovskite films. EDOT-assisted anti-solvent strategy aids to form high quality perovskite films with enlarged crystal grains and reduced defects via the interaction between oxygen and lead. The fabricated flexible and rigid solar cells delivered the power conversion efficiency of 15.58% and 20.12%, respectively, under AM 1.5 G illumination. The flexible and rigid devices also exhibited excellent indoor (@1000 lux) performance of 22.79% and 32.61%, respectively. The developed anti-solvent engineering provides a facial and effective strategy to fabricate low-cost flexible perovskite photovoltaics for indoor and outdoor applications.