Fluorinated End Group Enables High‐Performance All‐Polymer Solar Cells with Near‐Infrared Absorption and Enhanced Device Efficiency over 14%

Fluorination of end groups has been a great success in developing efficient small molecule acceptors. However, this strategy has not been applied to the development of polymer acceptors. Here, a dihalogenated end group modified by fluorine and bromine atoms simultaneously, namely IC‐FBr, is first developed, then employed to construct a new polymer acceptor (named PYF‐T) for all‐polymer solar cells (all‐PSCs). In comparison with its non‐fluorinated counterpart (PY‐T), PYF‐T exhibits stronger and red‐shifted absorption spectra, stronger molecular packing and higher electron mobility. Meanwhile, the fluorination on the end groups down‐shifts the energy levels of PYF‐T, which matches better with the donor polymer PM6, leading to efficient charge transfer and small voltage loss. As a result, an all‐PSC based on PM6:PYF‐T yields a higher power conversion efficiency (PCE) of 14.1% than that of PM6:PY‐T (11.1%), which is among the highest values for all‐PSCs reported to date. This work demonstrates the effectiveness of fluorination of end‐groups in designing high‐performance polymer acceptors, which paves the way toward developing more efficient and stable all‐PSCs.

[1]  H. Ade,et al.  Tailoring non-fullerene acceptors using selenium-incorporated heterocycles for organic solar cells with over 16% efficiency , 2020, Journal of Materials Chemistry A.

[2]  C. Zhong,et al.  Precisely Controlling the Position of Bromine on the End Group Enables Well‐Regular Polymer Acceptors for All‐Polymer Solar Cells with Efficiencies over 15% , 2020, Advanced materials.

[3]  B. Liu,et al.  A Narrow‐Bandgap n‐Type Polymer with an Acceptor–Acceptor Backbone Enabling Efficient All‐Polymer Solar Cells , 2020, Advanced materials.

[4]  Chunhui Duan,et al.  The new era for organic solar cells: polymer acceptors. , 2020, Science bulletin.

[5]  Kai Chen,et al.  Modulating Energy Level on an A‐D‐A′‐D‐A‐Type Unfused Acceptor by a Benzothiadiazole Core Enables Organic Solar Cells with Simple Procedure and High Performance , 2020 .

[6]  K. Wong,et al.  Selective Hole and Electron Transport in Efficient Quaternary Blend Organic Solar Cells , 2020, Joule.

[7]  W. Ma,et al.  All‐Polymer Solar Cells with over 12% Efficiency and a Small Voltage Loss Enabled by a Polymer Acceptor Based on an Extended Fused Ring Core , 2020, Advanced Energy Materials.

[8]  B. Liu,et al.  Reducing energy loss via tuning energy levels of polymer acceptors for efficient all-polymer solar cells , 2020, Science China Chemistry.

[9]  Xinhui Lu,et al.  Improved organic solar cell efficiency based on the regulation of an alkyl chain on chlorinated non-fullerene acceptors , 2020 .

[10]  Yanming Sun,et al.  Optimized active layer morphology toward efficient and polymer batch insensitive organic solar cells , 2020, Nature Communications.

[11]  A. Facchetti,et al.  High-Performance n-Type Polymer Semiconductors: Applications, Recent Development, and Challenges , 2020, Chem.

[12]  Wenkai Zhong,et al.  14.4% efficiency all-polymer solar cell with broad absorption and low energy loss enabled by a novel polymer acceptor , 2020 .

[13]  Wenyan Yang,et al.  Controlling Molecular Mass of Low-Band-Gap Polymer Acceptors for High-Performance All-Polymer Solar Cells , 2020 .

[14]  L. Meng,et al.  High Performance All-Polymer Solar Cells with the Polymer Acceptor Synthesized via a Random Ternary Copolymerization Strategy. , 2020, Angewandte Chemie.

[15]  Yang Yang,et al.  Narrowing the Band Gap: The Key to High-Performance Organic Photovoltaics. , 2020, Accounts of chemical research.

[16]  Fei Huang,et al.  Solution‐Processed Polymer Solar Cells with over 17% Efficiency Enabled by an Iridium Complexation Approach , 2020, Advanced Energy Materials.

[17]  Hongzheng Chen,et al.  New Phase for Organic Solar Cell Research: Emergence of Y-Series Electron Acceptors and Their Perspectives , 2020 .

[18]  W. Ma,et al.  Transannularly conjugated tetrameric perylene diimide acceptors containing [2.2]paracyclophane for non-fullerene organic solar cells , 2020 .

[19]  Shangfeng Yang,et al.  Progress of the key materials for organic solar cells , 2020, Science China Chemistry.

[20]  Wansun Kim,et al.  Mechanically Robust All-Polymer Solar Cells from Narrow Band Gap Acceptors with Hetero-Bridging Atoms , 2020 .

[21]  A. Mahmood,et al.  A bromine and chlorine concurrently functionalized end group for benzo[1,2-b:4,5-b′]diselenophene-based non-fluorinated acceptors: a new hybrid strategy to balance the crystallinity and miscibility of blend films for enabling highly efficient polymer solar cells , 2020 .

[22]  Zhenhua Chen,et al.  Delayed Fluorescence Emitter Enables Near 17% Efficiency Ternary Organic Solar Cells with Enhanced Storage Stability and Reduced Recombination Energy Loss , 2020, Advanced Functional Materials.

[23]  A. Jen,et al.  Graphdiyne Derivative as Multifunctional Solid Additive in Binary Organic Solar Cells with 17.3% Efficiency and High Reproductivity , 2020, Advanced materials.

[24]  Jun Liu,et al.  Organoboron Polymer for 10% Efficiency All-Polymer Solar Cells , 2020 .

[25]  Shangfeng Yang,et al.  18% Efficiency organic solar cells. , 2020, Science bulletin.

[26]  Bryon W. Larson,et al.  Simultaneously Improved Efficiency and Stability in All-Polymer Solar Cells by a P–i–N Architecture , 2019, ACS Energy Letters.

[27]  Bumjoon J. Kim,et al.  Recent Advances, Design Guidelines, and Prospects of All-Polymer Solar Cells. , 2019, Chemical reviews.

[28]  Jacek Ulanski,et al.  Single-Junction Organic Solar Cell with over 15% Efficiency Using Fused-Ring Acceptor with Electron-Deficient Core , 2019, Joule.

[29]  S. Jenekhe,et al.  New Random Copolymer Acceptors Enable Additive-Free Processing of 10.1% Efficient All-Polymer Solar Cells with Near-Unity Internal Quantum Efficiency , 2019, ACS Energy Letters.

[30]  G. Wang,et al.  All-Polymer Solar Cells: Recent Progress, Challenges, and Prospects. , 2019, Angewandte Chemie.

[31]  Christoph J. Brabec,et al.  Critical review of the molecular design progress in non-fullerene electron acceptors towards commercially viable organic solar cells. , 2019, Chemical Society reviews.

[32]  Yongqian Shi,et al.  High‐Performance All‐Polymer Solar Cells Enabled by an n‐Type Polymer Based on a Fluorinated Imide‐Functionalized Arene , 2019, Advanced materials.

[33]  C. Zhong,et al.  Achieving Balanced Charge Transport and Favorable Blend Morphology in Non-Fullerene Solar Cells via Acceptor End Group Modification , 2019, Chemistry of Materials.

[34]  F. Liu,et al.  A generic green solvent concept boosting the power conversion efficiency of all-polymer solar cells to 11% , 2019, Energy & Environmental Science.

[35]  H. Ade,et al.  Efficient All-Polymer Solar Cells based on a New Polymer Acceptor Achieving 10.3% Power Conversion Efficiency , 2019, ACS Energy Letters.

[36]  Yan Li,et al.  Suppression of Recombination Energy Losses by Decreasing the Energetic Offsets in Perylene Diimide-Based Nonfullerene Organic Solar Cells , 2018, ACS Energy Letters.

[37]  Xiaochen Wang,et al.  Aromatic‐Diimide‐Based n‐Type Conjugated Polymers for All‐Polymer Solar Cell Applications , 2018, Advanced materials.

[38]  Thomas Kirchartz,et al.  Optical Gaps of Organic Solar Cells as a Reference for Comparing Voltage Losses , 2018, Advanced Energy Materials.

[39]  Yongfang Li,et al.  Highly Flexible and Efficient All-Polymer Solar Cells with High-Viscosity Processing Polymer Additive toward Potential of Stretchable Devices. , 2018, Angewandte Chemie.

[40]  Yang Yang,et al.  Next-generation organic photovoltaics based on non-fullerene acceptors , 2018 .

[41]  He Yan,et al.  Design rules for minimizing voltage losses in high-efficiency organic solar cells , 2018, Nature Materials.

[42]  He Yan,et al.  Material insights and challenges for non-fullerene organic solar cells based on small molecular acceptors , 2018, Nature Energy.

[43]  Fei Huang,et al.  Nonfullerene Acceptor Molecules for Bulk Heterojunction Organic Solar Cells. , 2018, Chemical reviews.

[44]  K. Vandewal,et al.  How to determine optical gaps and voltage losses in organic photovoltaic materials , 2018 .

[45]  Seth R. Marder,et al.  Non-fullerene acceptors for organic solar cells , 2018 .

[46]  Feng Gao,et al.  Organic solar cells based on non-fullerene acceptors. , 2018, Nature materials.

[47]  Yongfang Li,et al.  Constructing a Strongly Absorbing Low-Bandgap Polymer Acceptor for High-Performance All-Polymer Solar Cells. , 2017, Angewandte Chemie.

[48]  He Yan,et al.  Improved Performance of All‐Polymer Solar Cells Enabled by Naphthodiperylenetetraimide‐Based Polymer Acceptor , 2017, Advanced materials.

[49]  Runnan Yu,et al.  Design, Synthesis, and Photovoltaic Characterization of a Small Molecular Acceptor with an Ultra-Narrow Band Gap. , 2017, Angewandte Chemie.

[50]  Thomas Kirchartz,et al.  Quantifying Losses in Open-Circuit Voltage in Solution-Processable Solar Cells , 2015 .