Coplanar phenanthro[9,10-d]imidazole based hole-transporting material enabling over 19%/21% efficiency in inverted/regular perovskite solar cells

A Multifunctional Fluorinated Polymer Enabling Efficient MAPbI3-Based Inverted Perovskite Solar Cells

“…This mild reaction condition provided a reproducible and controllable molecular weight, which was in favor of industrial production. As illustrated in SI Table S1, the synthetic cost of BN-12 was estimated to be $42.27 g –1 , which was 1 / 10 of the PTAA ($423 g –1 ). , …”

“…As displayed in Figure 6a, BN-6 exhibited shorter voltage decay quite inferior to BN-9 and BN-12, which was in good agreement with V oc values. Electrochemical impedance spectroscopy (EIS) was further implemented to investigate the electron recombination behavior inside the p-iPSCs with the bias ranging from 0.8 to 1.0 V. The charge recombination resistances (R rec ) derived from the low-frequency region of Nyquist plot were fitted by an equivalent circuit 27 and plotted in Figure 6b. It was demonstrated higher resistances for p-iPSCs fabricated with BN-9 and BN-12 as compared to that of BN-6 at any same absolute bias voltage.…”

“…To date, a large number of defect passivation strategies have been proposed. From 2019, in addition to endowing an additional passivation layer, exploring effective multifunctional hole-transporting materials (HTMs) with passivation functions has demonstrated to be a simplified and efficient method to alleviate the perovskite defects. ,− In comparison with small molecules, polymers exhibit better thermal stability, interfacial adhesion, and tunable energy levels, such as 2DP-TDB, PC6, PBDB-Cz, PBT1-C, PE10, PBDTT, P3, DTB­(x-DEG), PPY2, PTTI-TPA, etc. Nevertheless, most of the reported polymeric HTMs were applied to fabricate n-i-p regular PSCs.…”

Triarylamine-Functionalized Imidazolyl-Capped Bithiophene Hole Transporting Material for Cost-Effective Perovskite Solar Cells

“…Among them, organic HTMs are gaining considerable attention due to their tunable electronic properties, facile synthesis, and hydrophobicity. In particular, small-molecule HTMs have been widely explored owing to their definite structure and molecular weight, high purity, superior batch-to-batch synthetic reliability, and reproducibility. − Thus, diverse building blocks have been developed, such as thiophene, fluorene, carbazole, pyrene, and so forth, and functionalized to achieve HTMs with desirable performances. − In this context, functionalized imidazoles as HTMs have been scarcely studied. − Imidazole is a five-membered ring containing two nitrogen atoms, one pyrrole-like nitrogen and one pyridine-like nitrogen. The electron lone pair present on the pyrrole-like nitrogen contributes to aromaticity, whereas the pyridine-like nitrogen acts as a Lewis base that is advantageous for passivating the exposed Pb 2+ defects present over the periphery of perovskites via Lewis base–acid interactions .…”

“…The electron lone pair present on the pyrrole-like nitrogen contributes to aromaticity, whereas the pyridine-like nitrogen acts as a Lewis base that is advantageous for passivating the exposed Pb 2+ defects present over the periphery of perovskites via Lewis base−acid interactions. 39 Because imidazole is a weak donor, tethering triarylamine donors might improve hole transportation. For example, triarylamine endcapped imidazole compounds were employed as HTMs in dopant-free PSCs which have a PCE of 18.03% (Figure 1).…”