FeCl3 as a low-cost and efficient p-type dopant of Spiro-OMeTAD for high performance perovskite solar cells

Xiaoyu Gu; Yang Li; Yanfei Mu; Min Zhang; Tongbu Lu; Peng Wang

doi:10.1039/c8ra00243f

FeCl₃ as a low-cost and efficient p-type dopant of Spiro-OMeTAD for high performance perovskite solar cells

RSC Adv. 2018 Mar 5;8(17):9409-9413. doi: 10.1039/c8ra00243f. eCollection 2018 Feb 28.

Authors

Xiaoyu Gu^{1

2}, Yang Li^{2

3}, Yanfei Mu^{1

2}, Min Zhang¹, Tongbu Lu¹, Peng Wang²

Affiliations

¹ Institute for New Energy Materials & Low-Carbon Technologies, Tianjin University of Technology Tianjin 300384 China zm2016@email.tjut.edu.cn.
² Department of Chemistry, Zhejiang University Hangzhou 310028 China.
³ Changchun Institute of Applied Chemistry, Chinese Academy of Sciences Changchun 130022 China.

Abstract

Chemical doping is a viable tactic to improve the charge transporting properties of organic semiconductors in efficient perovskite solar cells. In this paper, we first employ the low-cost inorganic salt FeCl₃ as a chemical dopant to replace the traditional expensive cobalt complex for the oxidization of 2,2',7,7'-tetrakis(N,N-p-dimethoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD), a typical organic hole-transporter. Based on the joint measurements of electron absorption spectra, cyclic voltammetry, and the hole-only device, we reveal that FeCl₃ can effectively oxidize Spiro-OMeTAD and improve the hole transporting properties of Spiro-OMeTAD. Through carefully optimizing the dopant concentration, solar cells with 80% FeCl₃ doped Spiro-OMeTAD achieve over 17% power conversion efficiency based on a triple cation perovskite photoactive layer, which is comparable to that of devices with a classical cobalt complex dopant. Our work demonstrates the potential of using FeCl₃ as a low-cost chemical dopant for hole-transporting materials in perovskite solar cells.