Carbon Nanotubes for Energy

• Applicant: Dr. Benjamin Flavel
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation ; Solid State and Surface Chemistry, Material Synthesis
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 400008013

• Final Report Year: 2023

Final Report Abstract

Carbon nanotubes (CNTs) are a versatile material with multiple potential functions for photovoltaics. In principle, all elements of a solar cell, from the light sensitive component to carrier selective contacts, layers for passivation, and transparent conducting films can be replaced by carbon nanotubes. As such, this project has been aimed at developing techniques to enable the use of carbon nanotubes in each of these areas. CNT inks that can be directly spin cast onto silicon and form a ‘passivated charge selective contact’ (PCSC) were developed and these were used to fabricate CNT:Silicon solar cells with a power conversion efficiency (PCE) of over 23 %. In organic solar cells and as light sensitive elements, chirality pure CNTs were combined with new non-fullerene acceptors and in a ternary mix with the donor/acceptor PM6:Y6. Both bulk heterojunction and bilayer devices were fabricated and the SWCNTs were found to extend the light absorption of the solar cells into the infrared. A custom microfluidic setup capable of precise control over the filtration of SWCNTs was developed and this was used to create global and uniaxially aligned thin films of SWCNTs along with more sophisticated geometries, such as those with a radial symmetry.

Publications

• Breakthrough Carbon Nanotube–Silicon Heterojunction Solar Cells. Advanced Energy Materials, 10(1).
  Tune, Daniel D.; Mallik, Nitin; Fornasier, Heike & Flavel, Benjamin S.
  
• Separation of Small-Diameter Single-Walled Carbon Nanotubes in One to Three Steps with Aqueous Two-Phase Extraction. ACS Nano.
  Li, Han; Gordeev, Georgy; Garrity, Oisin; Reich, Stephanie & Flavel, Benjamin S.
  
• A Polymer/Carbon‐Nanotube Ink as a Boron‐Dopant/Inorganic‐Passivation Free Carrier Selective Contact for Silicon Solar Cells with over 21% Efficiency. Advanced Functional Materials, 30(38).
  Chen, Jianhui; Wan, Lu; Li, Han; Yan, Jun; Ma, Jikui; Sun, Biao; Li, Feng & Flavel, Benjamin S.
  
• Carbon Nanotubes for Photovoltaics: From Lab to Industry. Advanced Energy Materials, 11(3).
  Wieland, Laura; Li, Han; Rust, Christian; Chen, Jianhui & Flavel, Benjamin S.
  
• Emerging Materials for Energy Catalysis. Advanced Energy Materials, 10(11).
  Guo, Shaojun & Zhang, Qiang
  
• Global Alignment of Carbon Nanotubes via High Precision Microfluidic Dead‐End Filtration. Advanced Functional Materials, 32(10).
  Rust, Christian; Li, Han; Gordeev, Georgy; Spari, Manuel; Guttmann, Markus; Jin, Qihao; Reich, Stephanie & Flavel, Benjamin S.
  
• The potential of SWCNTs to extend the IR-absorption of silicon solar cells. Carbon, 184, 828-835.
  Wieland, L.; Rust, C.; Li, H.; Jakoby, M.; Howard, I.; Li, F.; Shi, J.; Chen, J. & Flavel, B.S.
  
• Ternary PM6:Y6 Solar Cells with Single‐Walled Carbon Nanotubes. Small Science, 3(2).
  Wieland, Laura; Li, Han; Zhang, Xuning; Chen, Jianhui & Flavel, Benjamin S.
  
• The Impact of Carbon Nanotube Length and Diameter on their Global Alignment by Dead‐End Filtration. Small, 19(10).
  Rust, Christian; Shapturenka, Pavel; Spari, Manuel; Jin, Qihao; Li, Han; Bacher, Andreas; Guttmann, Markus; Zheng, Ming; Adel, Tehseen; Walker, Angela R. Hight; Fagan, Jeffrey A. & Flavel, Benjamin S.
  
• Radial Alignment of Carbon Nanotubes via Dead‐End Filtration. Small, 19(19).
  Rust, Christian; Schill, Elias; Garrity, Oisín; Spari, Manuel; Li, Han; Bacher, Andreas; Guttmann, Markus; Reich, Stephanie & Flavel, Benjamin S.