Dithieno[3,2‐b:2′,3′‐d]pyrrol‐Cored Hole Transport Material Enabling Over 21% Efficiency Dopant‐Free Perovskite Solar Cells
Abstract
Dopant‐free hole transport materials (HTMs) are essential for commercialization of perovskite solar cells (PSCs). However, power conversion efficiencies (PCEs) of the state‐of‐the‐art PSCs with small molecule dopant‐free HTMs are below 20%. Herein, a simple dithieno[3,2‐b:2′,3′‐d]pyrrol‐cored small molecule, DTP‐C6Th, is reported as a promising dopant‐free HTM. Compared with commonly used spiro‐OMeTAD, DTP‐C6Th exhibits a similar energy level, a better hole mobility of 4.18 × 10−4 cm2 V−1 s−1, and more efficient hole extraction, enabling efficient and stable PSCs with a dopant‐free HTM. With the addition of an ultrathin poly(methyl methacrylate) passivation layer and properly tuning the composition of the perovskite absorber layer, a champion PCE of 21.04% is achieved, which is the highest value for small molecule dopant‐free HTM based PSCs to date. Additionally, PSCs using the DTP‐C6Th HTM exhibit significantly improved long‐term stability compared with the conventional cells with the metal additive doped spiro‐OMeTAD HTM. Therefore, this work provides a new candidate and effective device engineering strategy for achieving high PCEs with dopant‐free HTMs.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 15, 2019
- Source ID
- 10.1002/adfm.201904300
Entities
People
- Jianlong Zhou
- Niraj Shrestha
- Qinye Bao
- Randy J Ellingson
- Sandip Singh Bista
- Weihua Tang
- Xinxing Yin
- Yanfa Yan
- Zhaoning Song
- Zihao Dong
Organizations
- Air Force Research Laboratory
- China Scholarship Council
- East China Normal University
- Nanjing University of Science and Technology
- National Natural Science Foundation of China
- Office of Naval Research
- University of Toledo