Hybrid Fullerene-Based Electron Transport Layers Improving the Thermal Stability of Perovskite Solar Cells

Shu-Hui Li; Zhou Xing; Bao-Shan Wu; Zuo-Chang Chen; Yang-Rong Yao; Han-Rui Tian; Meng-Fan Li; Da-Qin Yun; Lin-Long Deng; Su-Yuan Xie; Rong-Bin Huang; Lan-Sun Zheng

doi:10.1021/acsami.0c02119

Hybrid Fullerene-Based Electron Transport Layers Improving the Thermal Stability of Perovskite Solar Cells

ACS Appl Mater Interfaces. 2020 May 6;12(18):20733-20740. doi: 10.1021/acsami.0c02119. Epub 2020 Apr 21.

Authors

Affiliations

¹ State Key Lab for Physical Chemistry of Solid Surfaces, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
² College of Energy, Xiamen University, Xiamen 361005, China.
³ Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China.

PMID: 32286057
DOI: 10.1021/acsami.0c02119

Abstract

The structure-dependent thermal stability of fullerene electron transport layers (ETLs) and its impact on device stability have been underrated for years. Based on cocrystallographic understanding, herein, we develop a thermally stable ETL comprising a hybrid layer of [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) and [6,6]-phenyl-C₆₁-propylbenzene (PCPB). By tuning the weight ratios of PCBM and PCPB to influence the noncovalent intermolecular interactions and packing of fullerene derivatives, we obtained a champion device based on the 20PCPB (20 wt % addition of PCPB into the mixture of PCBM/PCPB) ETL and excellent thermal stability of 500 h under 85 °C thermal aging in a N₂ atmosphere in the dark. The present work exemplifies that cocrystallography can be a precise tool to probe the interaction and aggregation of fullerene derivatives in ETLs, and mixed fullerene derivatives can be sought as promising ETLs to enhance the long-term stability of perovskite solar cells under high-temperature working environments.

Keywords: cocrystals; electron transport layer; fullerenes; perovskite solar cells; thermal stability.