Water-Soluble 2D Transition Metal Dichalcogenides as the Hole-Transport Layer for Highly Efficient and Stable p-i-n Perovskite Solar Cells

Peng Huang; Zhaowei Wang; Yanfeng Liu; Kaicheng Zhang; Ligang Yuan; Yi Zhou; Bo Song; Yongfang Li

doi:10.1021/acsami.7b06403

Water-Soluble 2D Transition Metal Dichalcogenides as the Hole-Transport Layer for Highly Efficient and Stable p-i-n Perovskite Solar Cells

ACS Appl Mater Interfaces. 2017 Aug 2;9(30):25323-25331. doi: 10.1021/acsami.7b06403. Epub 2017 Jul 19.

Authors

Peng Huang¹, Zhaowei Wang¹, Yanfeng Liu¹, Kaicheng Zhang¹, Ligang Yuan¹, Yi Zhou¹, Bo Song¹, Yongfang Li^{1

2}

Affiliations

¹ Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou 215123, China.
² Beijing National Laboratory of Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.

PMID: 28695726
DOI: 10.1021/acsami.7b06403

Abstract

As a hole-transport layer (HTL) material, poly(3,4-ethylenedioxythiophene):polystyrene-sulfonate (PEDOT:PSS) was often criticized for its intrinsic acidity and hygroscopic effect that would in the long run affect the stability of perovskite solar cells (Pero-SCs). As alternatives, herein water-soluble two-dimensional (2D) transition metal dichalcogenides (TMDs), such as MoS₂ and WS₂ were used as HTLs in p-i-n Pero-SCs. It was found that the content of 1T phase in 2D TMDs HTLs is centrally important to the power conversion efficiencies (PCEs) of Pero-SCs, and the 1T-rich TMDs (as achieved from exfoliation and without postheating) lead to much higher PCEs. More importantly, as PEDOT:PSS was replaced by 2D TMDs, both the PCEs and stability of Pero-SCs were significantly improved. The highest PCEs of 14.35 and 15.00% were obtained for the Pero-SCs with MoS₂ and WS₂, respectively, whereas the Pero-SCs with PEDOT:PSS showed a highest PCE of only 12.44%. These are up to date the highest PCEs using 2D TMDs as HTLs. After being stored in a glovebox for 56 days, PCEs of the Pero-SCs using MoS₂ and WS₂ HTLs remained 78 and 72%, respectively, whereas the PCEs of Pero-SCs with PEDOT:PSS almost dropped to 0 over 35 days. This study demonstrates that water-soluble 2D TMDs have great potential for application as new generation of HTLs aiming at high performance and long-term stable Pero-SCs.

Keywords: 1T phase; 2D transition metal dichalcogenides; hole-transport layer; improved stability; p−i−n perovskite solar cells.