Abstract
Hole-transporting materials (HTMs) play a critical role in realizing efficient and stable perovskite solar cells (PVSCs). Considering their capability of enabling PVSCs with good device reproducibility and long-term stability, high-performance dopant-free small-molecule HTMs (SM-HTMs) are greatly desired. However, such dopant-free SM-HTMs are highly elusive, limiting the current record efficiencies of inverted PVSCs to around 19%. Here, two novel donor–acceptor-type SM-HTMs (MPA-BTI and MPA-BTTI) are devised, which synergistically integrate several design principles for high-performance HTMs, and exhibit comparable optoelectronic properties but distinct molecular configuration and film properties. Consequently, the dopant-free MPA-BTTI-based inverted PVSCs achieve a remarkable efficiency of 21.17% with negligible hysteresis and superior thermal stability and long-term stability under illumination, which breaks the long-time standing bottleneck in the development of dopant-free SM-HTMs for highly efficient inverted PVSCs. Such a breakthrough is attributed to the well-aligned energy levels, appropriate hole mobility, and most importantly, the excellent film morphology of the MPA-BTTI. The results underscore the effectiveness of the design tactics, providing a new avenue for developing high-performance dopant-free SM-HTMs in PVSCs.
Original language | English |
---|---|
Article number | 1902781 |
Journal | Advanced Materials |
Volume | 31 |
Issue number | 35 |
DOIs | |
Publication status | Published - 2019 Aug |
Bibliographical note
Funding Information:Y.W. and W.C. contributed equally to this work. Y.W. acknowledges the financial support by the China Postdoctoral Science Foundation (No. 2018M630267), the National Natural Science Foundation of China (No. 21805128), and the SUSTech Presidential Postdoctoral Fellowship. H.S. thanks the National Natural Science Foundation of China (No. 21801124). X.G. is grateful to the National Natural Science Foundation of China (51573076) and the Shenzhen Basic Research Fund (JCYJ20170817105905899). Z.H. acknowledges the financial support of the National Natural Science Foundation of China (No. 61775091), the Natural Science Foundation of Shenzhen Innovation Committee (JCYJ20180504165851864), and the Shenzhen Key Laboratory Project (No. ZDSYS201602261933302). A.B.D. acknowledges support from the Shenzhen Innovation Committee (JCYJ20170818141216288) and the Seed Funding for Strategic Interdisciplinary Research Scheme of the University of Hong Kong. H.Y.W. acknowledges the financial support from the NRF of Korea (2016M1A2A2940911 and 2015M1A2A2057506).
Publisher Copyright:
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Keywords
- device stability
- donor–acceptor small molecules
- dopant-free hole-transporting materials
- inverted perovskite solar cells
ASJC Scopus subject areas
- General Materials Science
- Mechanics of Materials
- Mechanical Engineering