Enhancing Charge Generation in Nonfullerene Interdigitated Heterojunction Organic Solar Cells

Interdigitated heterojunction (IHJ) structures have recently been investigated as an alternatives to bulk heterojunction (BHJ) structures due to their better film morphology stability, reproducibility, and contact selectivity. Herein, the electrical and optical properties of a nonfullerene IHJ structure are investigated using drift diffusion and Maxwell equations and compared with other conventional structures. Based on simulation results, the IHJ structure demonstrates electrical advantages such as enhanced charge transport pathways and reduced nonradiative recombination and exhibits superior optical absorption profiles compared to the BHJ structure, owing to its photonic crystal‐like structure. A method is also proposed to further enhance the optical absorption of this structure by introducing a third organic material with absorption capabilities in the near‐infrared range, increasing the solar cell power conversion efficiency from 18.42% to over 19.5%.