Dopant‐Free Hole‐Transport Materials Based on Methoxytriphenylamine‐Substituted Indacenodithienothiophene for Solution‐Processed Perovskite Solar Cells

). A dopant-free, planar PSC that contained IDTT-TPA was fabricated and exhibited a high power conversion efficiency (PCE) of 15.7 %. This cell exhibited a higher PCE and less hysteresis than devices that contained IDT-TPA.