Enhanced Interface Compatibility by Ionic Dendritic Molecules To Achieve Efficient and Stable Perovskite Solar Cells

Lianlian Qi; Guozheng Du; Guojie Zhu; Yang Wang; Li Yang; Jinbao Zhang

doi:10.1021/acsami.3c07539

Enhanced Interface Compatibility by Ionic Dendritic Molecules To Achieve Efficient and Stable Perovskite Solar Cells

ACS Appl Mater Interfaces. 2023 Aug 30;15(34):41109-41120. doi: 10.1021/acsami.3c07539. Epub 2023 Aug 17.

Authors

Lianlian Qi¹, Guozheng Du¹, Guojie Zhu¹, Yang Wang¹, Li Yang^{1

2}, Jinbao Zhang^{1

2}

Affiliations

¹ College of Materials, Fujian Key Laboratory of Advanced Materials, Xiamen Key Laboratory of Electronic Ceramic Materials and Devices, Xiamen University, Xiamen 361005, China.
² Shenzhen Research Institute of Xiamen University, Shenzhen 518000, China.

PMID: 37590128
DOI: 10.1021/acsami.3c07539

Abstract

Poly(3-hexylthiophene) (P3HT) represents a promising hole transport material for emerging perovskite solar cells (PSCs) due to its appealing merits of high thermal stability and appropriate hydrophobicity. Nonetheless, large energy losses at the P3HT/perovskite interface lead to unsatisfied efficiency and stability of the devices. Herein, two ionic dendritic molecules, 3,3'-(2,7-bis(3,6-bis(bis(4-methoxyphenyl)amino)-9H-carbazol-9-yl)-9H-fluorene-9,9-diyl)bis(N,N,N-trimethylpropan-1-aminium) iodide and 3,3'-(2,7-bis(bis(4-(bis(4-methoxyphenyl)amino)phenyl)amino)-9H-fluorene-9,9-diyl)bis(N,N,N-trimethylpropan-1-aminium) iodide, namely, MPA-Cz-FAI and MPA-PA-FAI, are rationally designed as the interlayer to enhance interfacial compatibility. The dendritic backbone with conjugated structure endows the hole transport layer with high conductivity, derived from the more ordered microstructure with larger crystallization and higher connectivity of domain zones. Besides, a better energy level alignment is established between P3HT and perovskite, which enhances the charge extraction and transport yield. In addition, the peripheral methoxy groups enable effective defect passivation at the interface to suppress nonradiative recombination and the quaternary ammonium iodide serving as side chains enable efficient interfacial hole extraction contributing to enhanced charge collection yield. As a result, the dopant-free P3HT-based PSCs modified with MPA-Cz-PAI deliver a champion efficiency of 19.7%, significantly higher than that of the control devices (15.4%). More encouragingly, the unencapsulated devices demonstrate competitive environmental stability by retaining over 85% of its initial efficiency after 1500 h of storage under humid conditions (70% relative humidity). This work provides an effective molecular design strategy for interface engineering, envisaging a bright prospect for the further development of efficient and stable perovskite solar cells.

Keywords: P3HT; charge dynamics; film microstructure; interface modifier; perovskite solar cells.