Organic materials exhibit efficient light absorption and low‐temperature, large‐scale processability, and have stimulated enormous research efforts for next‐generation optoelectronics. While, high‐performance organic devices with fast speed and high responsivity still face intractable challenges, due to their intrinsic limitations including finite carrier mobility and high exciton binding energy. Here an ultrafast and highly sensitive broadband phototransistor is demonstrated by integrating high‐quality pentacene single crystal with monolayer graphene. Encouragingly, the −3 dB bandwidth can reach up to 26 kHz, which is a record‐speed for such sensitized organic phototransistors. Enormous absorption, long exciton diffusion length of pentacene crystal, and efficient interfacial charge transfer enable a high responsivity of >10⁵ A W⁻¹ and specific detectivity of >10¹¹ Jones. Moreover, self‐powered weak‐light detection is realized using a simple asymmetric configuration, and the obvious zero‐bias photoresponses can be displayed even under 750 nW cm⁻² light intensity. Excellent response speed and photoresponsivity enable high‐speed image sensor capability in UV‐Vis ranges. The results offer a practical strategy for constructing high‐performance self‐powered organic hybrid photodetectors, with strong applicability in wireless, weak‐light detection, and video‐frame‐rate imaging applications.

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 > 10 ³ A W ⁻¹ and specific detectivity of 10 ¹⁰ 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 > 10 ⁴ A W ⁻¹ and specific detectivity of > 10 ¹¹ 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.

Two-dimensional (2D) materials are competitive in a diverse range of areas, spanning from electronic and optoelectronic devices to wearable devices, due to their unique physical and chemical characteristics, as well as remarkable flexibility. As a typical 2D material, lead iodide (PbI₂), featuring a high atomic number and tunable band gap, has been extensively studied in many applications of electroluminescent (EL) devices, photodetectors, and perovskite solar cells. However, high-performance PbI₂-based photodetectors remain a challenge. Herein, we present a high-performance flexible photodetector based on 2D layered PbI₂ nanoplates, which were synthesized via a straightforward air sublimation method. The PbI₂-based photodetector exhibits an excellent photoresponse and the highest responsivity peaks at 34 A/W at 405 nm, together with an ultrahigh transient switching on/off current ratio of 10⁷. Due to a low dark current (10⁻¹⁴ A), the device exhibits an extremely low noise level (<10⁻²⁶ A²Hz⁻¹) and acceptable detectivity (2 × 10¹⁰ Jones). Furthermore, remarkable mechanical flexibility was observed in the device on a PET substrate, preserving both its electrical conductance and photoresponse stability after 560 bending cycles. Finally, high-resolution imaging applications were implemented under a 100 Hz modulated light signal. This work highlights the superior optoelectrical properties of 2D PbI₂ growth by the in-air sublimation method and proves its promising future in flexible and wearable optoelectronic devices.

Organic semiconductor materials featuring lightweight, and flexibility may play a significant role in various future applications, such as foldable displays, wearable devices, and artificial skin. For developing high-performance organic devices, organic crystals are highly desired, while a remaining fundamental issue is their contact problem. Here, we have grown a high-quality rubrene single crystal by utilizing a simple in-air sublimation technique. The contact characteristics (barrier height and contact resistance) are detail-studied by resist-free transfer electrodes (Au metal or graphene/Au). The Schottky barrier of the rubrene/graphene interface is lower and can be also modulated by gate bias, which is confirmed by spatial photocurrent mapping. Finally, we demonstrated the zero-bias photocurrent imaging application by constructing the asymmetrical device employing different electrode contacts. Our work would be of significance for studying the contact issue of organic crystals and wireless imaging.

Organic, single crystals have emerged as unique optoelectrical materials due to their highly ordered structure and low defects. In this work, pentacene nanoribbons and nanosheets were selectively fabricated by controlling their growth temperature. The results show that their photoluminescence (PL) activity and electrical properties were strongly dependent on their geometrical morphology and molecular stacking mode such as the degree of π-orbital overlap and intermolecular interaction. The pentacene nanoribbon crystal exhibited a higher PL intensity compared with the nanosheet configuration; conversely, its electrical conductivity was poor. The low-temperature PL measurement indicated that there are stronger π–π stacking interactions in the nanosheet crystal than in the nanoribbon crystal, leading to exciton quenching and higher conductivity. Our study demonstrated that a unique optoelectronic property of organic crystals can be obtained by controlling the crystal’s morphology, which offers potential guidance for the future design and development of organic crystal optoelectronics.