Sulfur-Rich Hole-Transporting Materials for Inverted Perovskite Solar Cells

We introduce an electron-rich hole-transporting material (HTM), WZ103, based on a sulfur-rich terthiophene core. This HTM features two triphenylamine donor groups at the 4,4″ positions and four additional triphenylamine groups at the 5,5″ positions connected by vinylene linkages. Its good hole-transporting properties, reduced series resistance, and effective defect passivation contribute to the improved performance. With a remarkable power conversion efficiency of 19.48%, this HTM ranks among the top nonfused terthiophene-based, dopant-free HTMs.