Introduction of Multifunctional Triphenylamino Derivatives at the Perovskite/HTL Interface To Promote Efficiency and Stability of Perovskite Solar Cells

Baohua Zhao; Xinyu Yan; Teng Zhang; Xiaotong Ma; Chengben Liu; Heyuan Liu; Keyou Yan; Yanli Chen; Xiyou Li

doi:10.1021/acsami.9b21112

Introduction of Multifunctional Triphenylamino Derivatives at the Perovskite/HTL Interface To Promote Efficiency and Stability of Perovskite Solar Cells

ACS Appl Mater Interfaces. 2020 Feb 26;12(8):9300-9306. doi: 10.1021/acsami.9b21112. Epub 2020 Feb 14.

Authors

Baohua Zhao¹, Xinyu Yan¹, Teng Zhang², Xiaotong Ma¹, Chengben Liu¹, Heyuan Liu³, Keyou Yan⁴, Yanli Chen², Xiyou Li²

Affiliations

¹ College of Science , China University of Petroleum (East China) , Qingdao 266580 , China.
² School of Materials Science and Engineering , China University of Petroleum (East China) , Qingdao 266580 , China.
³ Institute of New Energy , China University of Petroleum (East China) , Qingdao 266580 , China.
⁴ School of Environment and Energy, State Key Laboratory of Luminescent Materials and Devices, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment , South China University of Technology , Guangzhou 510006 , China.

PMID: 32000495
DOI: 10.1021/acsami.9b21112

Abstract

Surface passivation is a widely used approach to promote the efficiency and stability of perovskite solar cells (PSCs). In the present project, a series of new organic surface passivation molecules, which contain the same triphenylamino group with the hole transfer material of PSCs, have been synthesized. These new passivation molecules are supposed to have both "carrier transfer" capability and "defect passivation" potential. We find that, by using N-((4-(N,N,N-triphenyl)phenyl)ethyl)ammonium bromide (TPA-PEABr) as a surface passivation molecule, the efficiency of the PSCs can be improved from 16.69 to 18.15%, mainly due to an increased Voc (1.09 V compared with 1.02 V in control devices). The increased Voc is due to the reduced surface defect density and a better alignment for the related energy levels after introducing the TPA-PEABr molecules. Moreover, the stability of the PSCs can be significantly improved in TPA-PEABr passivated devices due to the hydrophobic nature of TPA-PEABr. Our results successfully demonstrate that passivation of the perovskite surface with a carefully designed multifunctional small organic molecule should be a useful approach for more stable PSCs with high efficiency.

Keywords: Energy level alignment; Perovskite solar cell; Stability; Surface passivation; Triphenylamine derivative.