Tuning Hole Transport Properties via Pyrrole Derivation for High‐Performance Perovskite Solar Cells

Abstract

Hole transport materials (HTMs) with high hole mobility, good band alignment and ease of fabrication are highly desirable for perovskite solar cells (PSCs). Here, we designed and synthesized novel organic HTMs, named T3, which can be synthesized in high yields with commercially available materials, featuring a substituted pyrrole core and triphenylamine peripheral arms. The capability of functionalization in the final synthetic step provides an efficient way to obtain a variety of T3‐based HTMs with tunable energy levels and other properties. Among them, fluorine‐substituted T3 (T3‐F) exhibits the best band alignment and hole extraction properties, leading to PSCs with outstanding PCEs of 24.85 % and 24.03 % (certified 23.46 %) for aperture areas of 0.1 and 1 cm2, respectively. The simple structure and tunable performance of T3 can inspire further optimization for efficient PSCs.

Understanding the Role of Fluorine Groups in Passivating Defects for Perovskite Solar Cells

“…In addition to these common groups, fluorines (F) with strong electronegativity, hydrophobic property, and high stability have also been introduced into the passivating materials to enhance the passivation effect. [8][9][10][11][12][13] For example, the F groups can directly interact with Pb 2 + defects to suppress interfacial recombination [14] or enhance the interaction between the additive molecule and the perovskite film for reducing defect densities of perovskite. [15] It has also been reported that the F groups can form a large molecular dipole within the passivator, providing a directional field for charge separations, [16] or form hydrogen bonds between the passivator and methylamine ion to inhibit ion migration in the perovskite film.…”

Inhibiting Li+migration by thenoyltrifluoroacetone toward efficient and stable perovskite solar cells

“…28,29 Therefore, when n is smaller, a device is closer to the ideal device, and the non-radiative coincidence is smaller. 30 After TTA modification, the ideality factor decreased from 1.79 to 1.24, indicating the reduced nonradiative recombination due to TTA. As revealed in Fig.…”

Solvent-free synthetic protocols for halide perovskites

“…, Cu:NiO x with a thin layer of an organic polymer, PhNa-1T), that offer improved stability and interface properties. 108,109 These materials can potentially address the shortcomings of conventional HTL materials like PEDOT:PSS and PTAA, ultimately leading to more efficient and stable PSCs.…”

“…Recent advances in HTL materials have led to the development of novel alternatives, such as inorganic materials (e.g., triphenylamine-containing pyrrole-based HTM T3) or hybrid organic-inorganic compounds (e.g., Cu:NiO x with a thin layer of an organic polymer, PhNa-1T), that offer improved stability and interface properties. 108,109 These materials can potentially address the shortcomings of conventional HTL materials like PEDOT:PSS and PTAA, ultimately leading to more efficient and stable PSCs.…”