Near‐Infrared Small Molecule Acceptor Enabled High‐Performance Nonfullerene Polymer Solar Cells with Over 13% Efficiency

One of the most promising approaches to achieve high‐performance polymer solar cells (PSCs) is to develop nonfullerene small molecule acceptors (SMAs) with an absorption extending to the near‐infrared (NIR) region. In this work, two novel SMAs, namely, BTTIC and BTOIC, are designed and synthesized, with optical bandgaps (Egopt) of 1.47 and 1.39 eV, respectively. Desipte the narrow Egopt, the PBDB‐T:BTTIC‐ and PBDB‐T:BTOIC‐based PSCs can maintain high VOCs of over 0.90 and 0.86 V, respectively, with low energy losses (Eloss) < 0.6 eV. Meanwhile, due to the favorable morphology of the PBDB‐T:BTTIC blend, balanced carrier mobilities are achieved. The high external quantum efficiencies enable a high power conversion efficiency (PCE) up to 13.18% for the PBDB‐T:BTTIC‐based PSCs. In comparison, BTOIC shows an excessive crystallization propensity owing to its oxyalkyl side groups, which eventually leads to a relatively low PCE for the PBDB‐T:BTOIC‐based PSCs. Overall, this work provides insights into the design of novel NIR‐absorbing SMAs for nonfullerene PSCs.

[1]  H. Ade,et al.  Multiple Cases of Efficient Nonfullerene Ternary Organic Solar Cells Enabled by an Effective Morphology Control Method , 2018 .

[2]  H. Ade,et al.  Effect of Alkylsilyl Side‐Chain Structure on Photovoltaic Properties of Conjugated Polymer Donors , 2018 .

[3]  F. Liu,et al.  Fine‐Tuning of Molecular Packing and Energy Level through Methyl Substitution Enabling Excellent Small Molecule Acceptors for Nonfullerene Polymer Solar Cells with Efficiency up to 12.54% , 2018, Advanced materials.

[4]  F. Liu,et al.  An Unfused‐Core‐Based Nonfullerene Acceptor Enables High‐Efficiency Organic Solar Cells with Excellent Morphological Stability at High Temperatures , 2018, Advanced materials.

[5]  R. Friend,et al.  Fine‐Tuning the Energy Levels of a Nonfullerene Small‐Molecule Acceptor to Achieve a High Short‐Circuit Current and a Power Conversion Efficiency over 12% in Organic Solar Cells , 2018, Advanced materials.

[6]  W. Ma,et al.  Realizing Over 13% Efficiency in Green‐Solvent‐Processed Nonfullerene Organic Solar Cells Enabled by 1,3,4‐Thiadiazole‐Based Wide‐Bandgap Copolymers , 2018, Advanced materials.

[7]  W. Ma,et al.  Naphthodithiophene‐Based Nonfullerene Acceptor for High‐Performance Organic Photovoltaics: Effect of Extended Conjugation , 2018, Advanced materials.

[8]  T. Marks,et al.  Enhancing Indacenodithiophene Acceptor Crystallinity via Substituent Manipulation Increases Organic Solar Cell Efficiency , 2017 .

[9]  H. Ade,et al.  Design of a New Small‐Molecule Electron Acceptor Enables Efficient Polymer Solar Cells with High Fill Factor , 2017, Advanced materials.

[10]  S. Forrest,et al.  High Efficiency Near-Infrared and Semitransparent Non-Fullerene Acceptor Organic Photovoltaic Cells. , 2017, Journal of the American Chemical Society.

[11]  H. Ade,et al.  Ring-Fusion of Perylene Diimide Acceptor Enabling Efficient Nonfullerene Organic Solar Cells with a Small Voltage Loss. , 2017, Journal of the American Chemical Society.

[12]  Liming Ding,et al.  Ternary organic solar cells offer 14% power conversion efficiency. , 2017, Science bulletin.

[13]  Zhishan Bo,et al.  Fused‐Ring Acceptors with Asymmetric Side Chains for High‐Performance Thick‐Film Organic Solar Cells , 2017, Advanced materials.

[14]  F. Liu,et al.  A Twisted Thieno[3,4‐b]thiophene‐Based Electron Acceptor Featuring a 14‐π‐Electron Indenoindene Core for High‐Performance Organic Photovoltaics , 2017, Advanced materials.

[15]  Yun Zhang,et al.  Improved Domain Size and Purity Enables Efficient All‐Small‐Molecule Ternary Solar Cells , 2017, Advanced materials.

[16]  Fujun Zhang,et al.  Side Group Engineering of Small Molecular Acceptors for High‐Performance Fullerene‐Free Polymer Solar Cells: Thiophene Being Superior to Selenophene , 2017 .

[17]  W. Ma,et al.  Enhancing Performance of Nonfullerene Acceptors via Side‐Chain Conjugation Strategy , 2017, Advanced materials.

[18]  H. Ade,et al.  Achieving Highly Efficient Nonfullerene Organic Solar Cells with Improved Intermolecular Interaction and Open‐Circuit Voltage , 2017, Advanced materials.

[19]  H. Yao,et al.  Fine-Tuned Photoactive and Interconnection Layers for Achieving over 13% Efficiency in a Fullerene-Free Tandem Organic Solar Cell. , 2017, Journal of the American Chemical Society.

[20]  Yun Zhang,et al.  Molecular Optimization Enables over 13% Efficiency in Organic Solar Cells. , 2017, Journal of the American Chemical Society.

[21]  Wei You,et al.  Single‐Junction Binary‐Blend Nonfullerene Polymer Solar Cells with 12.1% Efficiency , 2017, Advanced materials.

[22]  Yongsheng Chen,et al.  Small-Molecule Acceptor Based on the Heptacyclic Benzodi(cyclopentadithiophene) Unit for Highly Efficient Nonfullerene Organic Solar Cells. , 2017, Journal of the American Chemical Society.

[23]  Fujun Zhang,et al.  Highly Efficient Parallel-Like Ternary Organic Solar Cells , 2017 .

[24]  A Novel Thiophene‐Fused Ending Group Enabling an Excellent Small Molecule Acceptor for High‐Performance Fullerene‐Free Polymer Solar Cells with 11.8% Efficiency , 2017, 1703.02896.

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

[26]  C. J. M. Emmott,et al.  Reducing the efficiency-stability-cost gap of organic photovoltaics with highly efficient and stable small molecule acceptor ternary solar cells. , 2017, Nature materials.

[27]  Chunru Wang,et al.  Fused Nonacyclic Electron Acceptors for Efficient Polymer Solar Cells. , 2017, Journal of the American Chemical Society.

[28]  Yongfang Li,et al.  Side-Chain Isomerization on an n-type Organic Semiconductor ITIC Acceptor Makes 11.77% High Efficiency Polymer Solar Cells. , 2016, Journal of the American Chemical Society.

[29]  Yongfang Li,et al.  Non-fullerene polymer solar cells based on a selenophene-containing fused-ring acceptor with photovoltaic performance of 8.6% , 2016 .

[30]  Long Ye,et al.  Energy‐Level Modulation of Small‐Molecule Electron Acceptors to Achieve over 12% Efficiency in Polymer Solar Cells , 2016, Advanced materials.

[31]  H. Ade,et al.  Fast charge separation in a non-fullerene organic solar cell with a small driving force , 2016, Nature Energy.

[32]  Daoben Zhu,et al.  An Electron Acceptor Challenging Fullerenes for Efficient Polymer Solar Cells , 2015, Advanced materials.

[33]  Xiaowei Zhan,et al.  Non-fullerene acceptors for organic photovoltaics: an emerging horizon , 2014 .

[34]  Wei Li,et al.  Electrochemical Considerations for Determining Absolute Frontier Orbital Energy Levels of Conjugated Polymers for Solar Cell Applications , 2011, Advanced materials.

[35]  C. Brabec,et al.  Origin of the Open Circuit Voltage of Plastic Solar Cells , 2001 .