Sulfonated Dopant‐Free Hole‐Transport Material Promotes Interfacial Charge Transfer Dynamics for Highly Stable Perovskite Solar Cells

Abstract

The integration of a functional group into dopant‐free hole‐transport materials (HTMs) to modify the perovskite|HTM interface has become a promising strategy for high‐performance and stable perovskite solar cells (PSCs). In this work, a sulfonated phenothiazine‐based HTM is reported, namely TAS, which consists of a butterfly structure with a readily synthesized N,​N‐​bis[4‐​(methylthio)​phenyl]​aniline side functional group. The interaction between TAS and perovskite via Pb–S bond induces a dipole moment that deepens the valence band of perovskite and thereby leads to enhanced open‐circuit voltage in corresponding n‐i‐p PSCs. More importantly, the functionalization of perovskite surface via Pb–S bond promotes the hole extraction reaction while suppressing the interfacial non‐radiative recombination, contributing to a 20–50% performance improvement compared to less‐ (4‐​(methylthio)​‐​N‐​[4‐​(methylthio)​phenyl]​aniline, DAS) or non‐interacting (N,N‐bis(4‐methoxyphenyl)aniline, TAO) counterparts. Consequently, TAS‐based PSCs exhibit superior device stability with a high PCE retention (>90% of the initial value) after 125 days of storage in the air.

Deep Eutectic Solvents in Solar Energy Technologies

“…Among the solar energy conversion technologies, Dye-Sensitized Solar Cells (DSSCs) are the devices that offer the greatest possibility of intervention to improve their properties, both in terms of environmental sustainability and in terms of performance in the conversion of energy. In the last decade, perovskite solar cells (PSCs) have emerged as novel PV devices with promise of high efficiency, comparable to Si-crystalline cells, at low manufacturing costs [ 7 , 8 , 9 , 10 , 11 , 12 ].…”

Composited Film of Poly(3,4-ethylenedioxythiophene) and Graphene Oxide as Hole Transport Layer in Perovskite Solar Cells

“…Finally, the mass ratio of PEDOT / GO is determined to be 0.75, the film quality and hole transport performance of the composites reach a balance, and the highest PCE is obtained. In addition, the hysteresis in the J-V curve of PEDOT-GO based devices is significantly reduced compared with the HTL-free devices (Figure 3c) [26]. PEDOT-GO composite material effectively optimized the hole extraction and transfer ability of the device, and reduces the built-in electric field at the interface of perovskite and HTL.…”

In Situ Ethanolamine ZnO Nanoparticle Passivation for Perovskite Interface Stability and Highly Efficient Solar Cells

“…On the other hand, as HTL, Spiro-OMeTAD (2,2′,7,7,7′-tetrakis(N,N′-di-p-methoxyphenlamine)-9,9-spirobifluorene), and PTAA (poly-triarylamine) are commonly used with dopants such as Li-TFSI (bis(trifluoromethane)sulfonimide lithium salt) to increase their charge mobility and conductivity; however, this can lead to device degradation [ 10 , 11 ] due to oxidation related to unwanted ion migration and a chemical interaction with the perovskite. For this reason, strategies based on sulfonated phenothiazine-based are investigated to create strong Pb-S bonds to stabilize the whole device [ 12 , 13 ].…”