Transient Dipole Strategy Boosts Highly Oriented Self-Assembled Monolayers for Organic Solar Cells Approaching 21% Efficiency

Self-assembled monolayers (SAMs) based on carbazole with minimal parasitic absorption, such as the most widely used [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), dominate the high-performance hole transport layer (HTL) for conventional organic solar cells (OSCs). However, the small dipole moment of the 2PACz molecules results in weak molecular dipole-dipole interactions, leading to disordered dipole orientation and restricting work function modulation, which causes serious interfacial energy loss. Here, we grafted thiophene groups at both ends of the carbazole in 2PACz to obtain an SAM material (Th-Cz), which formed a transient resonance structure during thermal annealing, resulting in a twice-enlarged…

• NN
  National Natural Science Foundation of China

  Awards: 22309129, 52273188
• JS
  Jiangsu Science and Technology Department

  Award: BE2022023
• PA
  Priority Academic Program Development of Jiangsu Higher Education Institutions
• CI
  Collaborative Innovation Center of Suzhou Nano Science and Technology
• CN
  China National Funds for Distinguished Young Scientists

  Award: 52325307