Highly-Polarized Near-Infrared Photodetector Based on 2D Organic/Inorganic Van Der Waals Heterostructure

Organic semiconductors have demonstrated exceptional performance due to their inherent advantages such as simple processability, and superior mechanical properties. Developing polarization-sensitive near-infrared (NIR) organic photodetectors is crucial for their application in target recognition, biological imaging, and wearable optoelectronics. However, high-performance NIR photon detection still faces challenges for organic materials, due to their intrinsic limitations including low carrier mobility, and poor exciton dissociation. Here, a polarization-sensitive NIR photodetector is demonstrated with a linear dichroic ratio of 5.3, employing a two-dimensional (2D) TiOPc single-crystal/graphene heterostructure. Remarkable absorption, optimized exciton diffusion of single crystal, and efficient interfacial charge transfer enable a high NIR responsivity of > 10³ A W^-1 and specific detectivity of 10¹⁰ Jones for 980 nm irradiation, with a reasonable -3 dB bandwidth of >1 kHz. Under 850 nm illumination, it exhibits an even higher responsivity of > 10⁴ A W^-1 and specific detectivity of > 10¹¹ Jones, attributed to stronger absorption. This NIR responsivity represents a tenfold improvement over existing organic polarization photodetectors. Finally, the high-resolution polarization-dependent single-pixel imaging in NIR range is achieved, highlighting its great potential for image recognition applications. This work opens new avenues for exploiting high-performance NIR polarized photodetectors.