This review explores different paths to replace traditional HTMs, it discusses recent advancements in conjugated organic-HTMs, organic-SAMs and polymeric-HTMs, aiming to improve the efficiency and stability of lead and tin-based PSCs.
Several HTMs have been designed by adding various types of π-conjugation group on both sides of the planar core of reference HTM, resulting that charge transfer integral is the dominant factor which mainly influence the hole mobility.
Based on the D–A–D scaffold, six benzothiadiazole-based HTMs are tailored by using phenoxazine, phenothiazine and carbazole as the donors, and their electronic, optical, hole-transporting and interfacial properties are evaluated theoretically.
A novel thiadiazolophenanthroline unit is exploited as the acceptor of D–A–D HTMs, and newly designed SM-4 shows much better performance than typical SM-1 in terms of energy levels, mobility and interfacial properties.
The development of a new structure is one of the important approaches for the advancement of efficient hole-transporting materials (HTMs).