Effect of 1,3-Disubstituted Urea Derivatives as Additives on the Efficiency and Stability of Perovskite Solar Cells

Additive engineering in perovskites precursor solution is one of the most effective methods to fabricate high-quality perovskite films. Finding proper additives for morphology improvement and passivation defects critical highly efficient stable solar cells (PSCs). In this work, 1,3-disubstituted urea are employed study effect different substituents at −NH moiety on quality layer device performance. By adding 1,3-diphenyl (Ph-urea) or 1,3-di(tert-butyl)urea (tBu-urea) into precursors, crystallization process leads formation films with larger grains lower defect densities as compared nonsubstituted additive. Using density functional theory (DFT) calculations experimental spectroscopic measurements, we found that selected ureas prone form stronger coordination interaction undercoordinated Pb2+ ions than urea. Applying additive devices reduced current density–voltage (J–V) hysteresis improved photovoltaic performance, resulting maximum power conversion efficiencies 21.7 21.2% Ph-urea tBu-urea modified devices, respectively. addition, enhanced long-term stability, where it remains 90% its initial efficiency, while degrades fast reaching 20% efficiency after aging 90 days due high moisture permeability tBu-urea.