Enhancing structural and optical properties of hybrid perovskite layers with polymer modification

Incorporating polymer additives into hybrid perovskite solar cells is an effective strategy to enhance stability while retaining high efficiency. This study examines the impact of three polymers: polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and polyvinyl alcohol (PVA) added at varying concentrations on the stability of perovskite as the absorber layer. Structural, optical, and electrochemical analyses demonstrate that adding PEG 0.3 mg/ml significantly improves perovskite films' morphology, light absorption, and charge transport while reducing recombination losses and enhancing long-term stability. Specifically, at room temperature and 30% relative humidity, the optimized perovskite sample with 0.3 mg/mL PEG maintained stability for up to 1000 h. Additionally, The UV analysis determined the band gap to be 1.58 eV. The electrochemical impedance spectroscopy analysis evaluated the charge transfer resistance (Rct) to be 1408 Ωcm², lower than other samples modified with polymer. The findings reveal that polymer modification significantly enhances the stability and efficiency of perovskite solar cells, improving their reliability and market competitiveness.