V-shaped hole-transporting TPD dimers containing Tröger’s base core

V-shaped hole transporting materials based on N,N,N′,N′-tetraarylbenzidine (TPD)-type moieties conjoined by Tröger’s base core were synthesized and investigated. These hole transporting materials were obtained by a three-step synthetic method, are fully amorphous, and demonstrate high glass transition temperatures and good thermal and morphological stability. Relatively high charge mobility (up to 0.036 cm2 V –1 s–1) was measured in these hole transporting materials, exceeding that of corresponding methyl and methoxy substituted TPD analogues without TB core by more than 2 orders of magnitude. Determined ionization potential and charge mobility values permit use of the synthesized compounds as hole transporting materials in fabrication of perovskite solar cells

Passivating Defects of Perovskite Solar Cells with Functional Donor-Acceptor-Donor Type Hole Transporting Materials

In this study, a series of donor-acceptor-donor (D-A-D) type small molecules based on the fluorene and diphenylethenyl enamine units, which are distinguished by different acceptors, as holetransporting materials (HTMs) for perovskite solar cells is presented. The incorporation of the malononitrile acceptor units is found to be beneficial for not only carrier transportation but also defects passivation via Pb-N interactions. The highest power conversion efficiency of over 22% is achieved on cells based on V1359, which is higher than that of spiro-OMeTAD under identical conditions. This st shows that HTMs prepared via simplified synthetic routes are not only a low-cost alternative to spiro-OMeTAD but also outperform in efficiency and stability state-of-art materials obtained via expensive cross-coupling methods