Chiral Nanographene Imides: Balancing the Dissymmetry Factor‐Mobility Trade‐Off Towards Circularly Polarization‐Sensitive Photodetection

ABSTRACT

Chiral small‐molecule organic semiconductors are attractive for circularly polarized light (CPL) detection owing to their tunable functionality and versatile processability. However, their intrinsic trade‐off between large dissymmetry factor and high carrier mobility ( μ ) hinders the application for high‐performance CPL detection. To overcome this issue, the chiral induction combined with the ring‐fusion strategy is employed to rationally construct a new n‐type chiral nanographene imide ( S )‐Cy‐FT‐FPDI. In the monomeric state, ( S )‐Cy‐FT‐FPDI exhibited distinct circular dichroism (CD) signals, with the maximum absorption dissymmetry factor ( g _abs ) reaching −2.16 × 10 ⁻³ . The ( S )‐Cy‐FT‐FPDI annealed thin films presented dual‐wavelength CPL responses at 455 and 595 nm, with photocurrent dissymmetry factors ( g _ph ) of 0.22 and 0.53, respectively, while delivering high μ of 0.57 cm ² V ⁻¹ s ⁻¹ , successfully balancing the favorable electrical performance and excellent chiroptical property. Remarkably, the achieved μ and g _ph outperform most of the previously reported chiral organic small‐molecule counterparts. Then, we have successfully demonstrated the high‐fidelity encoding and encryption based on ( S )‐Cy‐FT‐FPDI annealed thin films. Our work provides a feasible molecular design strategy for chiral organic small molecules with concurrent high g _ph and μ , balancing the dissymmetry factor‐mobility trade‐off towards high‐performance CPL detection.