Molecular packing regulation of dopant-free hole transport polymers for efficient perovskite solar cells
Hang Liu,
Yuping Gao,
Yufei Xin,
Hao Zhang,
Yu Zou,
Xiyue Dong,
Yanhong Lu,
Qiang Fu,
Yongsheng Liu
Affiliations
Hang Liu
Key Laboratory of Functional Polymer Materials, The Centre of Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
Yuping Gao
Key Laboratory of Functional Polymer Materials, The Centre of Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
Yufei Xin
Key Laboratory of Functional Polymer Materials, The Centre of Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
Hao Zhang
Key Laboratory of Functional Polymer Materials, The Centre of Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
Yu Zou
Key Laboratory of Functional Polymer Materials, The Centre of Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
Xiyue Dong
Key Laboratory of Functional Polymer Materials, The Centre of Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
Yanhong Lu
School of Chemistry & Material Science, Langfang Normal University, Langfang 065000, China
Qiang Fu
Key Laboratory of Functional Polymer Materials, The Centre of Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China; Department of Materials Science and Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong; Corresponding authors.
Yongsheng Liu
Key Laboratory of Functional Polymer Materials, The Centre of Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China; Renewable Energy Conversion and Storage Center (RECAST), Nankai University, Tianjin 300071, China; Corresponding authors.
Spiro-OMeTAD is a primary hole transport material (HTM) employed in most state-of-the-art regular perovskite solar cells (PSCs). The essential reliance on hygroscopic ionic dopants to enhance the conductivity and mobility of Spiro-OMeTAD has dramatically compromised the stability of PSCs. Here, we demonstrated excellent photovoltaic performance of PSCs by developing two dopant-free polymers, namely L1 and L2, using thieno[3,2-b]thiophene as a building block. It is found that the n-hexyl-modified thiophene side chains endow the polymer L2 with favorable crystallinity, unique self-assembly behavior, and a preferable face-on stacking orientation. After the addition of a small amount (10 %) of PM6 to create a polymer alloy named LPA, the above properties were further improved, and the resulting film exhibited a distinct fibrous morphology, resulting in increased hole mobility and effective defect passivation. Consequently, PSCs employing LPA as a dopant-free HTM afforded a high efficiency of 23.81 %. Importantly, LPA-based PSCs exhibit significantly enhanced operational stability with a T80 lifetime of 1572 h at 55 °C. This work provides a crucial guideline for the design of dopant-free polymers, thereby advancing the practical application of PSCs.
