Molecular Engineering of Hexaazatriphenylene Derivatives toward More Efficient Electron-Transporting Materials for Inverted Perovskite Solar Cells

Abstract

The electron-transporting material (ETM) in inverted perovskite solar cells (PSCs) plays important role in reducing hysteresis and realizing simple processing procedures, while the improvement of power conversion efficiency is limited by low electron mobility and weak perovskite/ETM interface interaction. In this work, three new ETMs (HAT-1, HAT-2, and HAT-3) were designed by introducing methoxyphenyl, imide, and naphthalene groups into the hexaazatriphenylene (HAT) skeleton, based on the ETM HATNASOC7 synthesized experimentally [Jen; et al. Angew. Chem., Int. Ed. 2016, 55, 8999]. Theoretical calculations showed that the electron mobilities of HAT-1, HAT-2, and HAT-3 are 2.98, 3.79, and 13.21 times that of HATNASOC7, which is attributed to the increased C•••C and O•••H interactions in the newly designed ETMs. More importantly, the evidently decreased perovskite/ETM interface distances and the significantly increased adsorption energies revealed that the interface interactions were markedly enhanced with the newly designed ETMs by forming additional Pb••• O interactions, which promote the electron injection. The deep understanding of perovskite/ ETM interface properties sheds new light on the complex factors determining the PSC function and paves the way for the rational design of highly efficient and stable components for PSCs.

Pentadiamond: A Highly Efficient Electron Transport Layer for Perovskite Solar Cells

“…To obtain the stable geometry of pentadiamond, different van der Waals (vdW) functionals (DFT-D3, optB86b-vdW) are combined with the Perdew–Burke–Ernzerhof (PBE) exchange–correlation functional in the optimization calculation to provide a better description of vdW interactions. The combination of PBE with vdW functionals has been widely used to study the structural and electronic properties of all-carbon materials. − Our results indicate that both vdW functionals show similar results for the lattice parameter and the various bond lengths and angles (Table S1), although results from the optB86b-vdW method do give a better match with reported data . Besides, our previous work on another carbon allotrope T-carbon has manifested that the optB86b-vdW functional provides a better improvement in the description of geometric parameters .…”

Molecular Engineering in Perovskite Solar Cells: A Computational Study on 2‐Mercaptopyridine Derivatives as Surface Passivators against Water

“…[14b,c] The adsorption energy (E ads ) was calculated to evaluate the strength of interaction between PMs and perovskite surfaces, which is defined as the difference between the energy of PM@MAPbI 3 and that of PMs and MAPbI 3 . [23] The adsorption of all the PMs onto the perovskite surface is spontaneous with negative adsorption energies. The more negative E ads indicates the stronger interaction [14c, 23,24] and the more durable passivation effect.…”

“…[23] The adsorption of all the PMs onto the perovskite surface is spontaneous with negative adsorption energies. The more negative E ads indicates the stronger interaction [14c, 23,24] and the more durable passivation effect. The E ads absolute values of PMs on the perovskite surfaces are 0.39, 0.92, 1.37, 1.07, and 1.14 eV, respectively for 2-MP, 2-MEP, 2-MDEP, 2-MTEP, and 2-MQEP, which gradually increase and then decrease with the extension of the carbon chain.…”

Recent Advancements of Hexaazatriphenylene-Based Materials for Energy Applications

“…超级电容器既具有电容器快速充放电的特性, 同时 又具有电池的储能特性. 为满足车辆和便携式电子设备 供电的需求, 超级电容器的研究备受青睐 [46] , HAT 衍生 图 10 HAT 衍生物用于钙钛矿太阳能电池 [44][45] Figure 10 HAT derivatives are used in perovskite solar cells (a) The structure of HATNASOC7-C S , the J-V curve comparison chart of PVSC prepared with ETM and their PCE; (b) three HAT derivative structures prepared by Li's group 物也可以作为超级电容器材料. 在 2011 年, 江东林课题 组 [47] 通过苯四胺与环己六酮的离子热反应构建了具有 内置氮杂单元的多孔框架 Aza-CMP(图 11).…”