Sulfonyldibenzene-based hole-transporting materials for efficient n-i-p perovskite solar cells

Organic hole-transporting materials (HTMs) are an essential component in conventional perovskite solar cells (PSCs). In this work, two sulfonyldibenzene-based molecules, named CS-04 and CS-05, are synthesized and employed as HTMs in n-i-p PSCs. In comparison with CS-04, the carbazole-substituted methoxytriphenylamine (CzMOTPA) group in CS-05 exhibits an increased degree of molecular distortion, thus endowing CS-05 with excellent solvent solubility and film-formation ability. Moreover, CS-05 shows a high hole mobility, superior hole extraction and hole transporting properties. As a result, CS-05 yields impressive device performances with a high power conversion efficiency (PCE) of 20.15%, while that of CS-04 based device is 19.50%, which is comparable to that of the Spiro-OMeTAD based control device (19.59%). This finding illustrates the potential of sulfonyldibenzene-based molecules for the applications in PSCs, and also provides a novel avenue to improve the performances and stability of PSCs by tailoring the sulfonyldibenzene-based molecules.