Hybrid materials in optoelectronic devices can generate new functionality or provide synergistic effects that enhance the properties of each component. Here, high-performance phototransistors with broad spectral responsivity in UV-vis-near-infrared (NIR) regions, using gold nanorods (Au NRs)-decorated n-type organic semiconductor and N,N′-bis(2-phenylethyl)-perylene-3,4:9,10tetracarboxylic diimide (BPE-PTCDI) nanowires (NWs) are reported. By way of the synergistic effect of the excellent photo-conducting characteristics of single-crystalline BPE-PTCDI NW and the light scattering and localized surface plasmon resonances (LSPR) of Au NRs, the hybrid system provides new photodetectivity in the NIR spectral region. In the UV-vis region, hybrid nanomaterial-based phototransistors exhibit significantly enhanced photo-responsive properties with a photo-responsivity (R) of 7.70 × 10 5 A W −1 and external quantum efficiency (EQE) of 1.42 × 10 8 % at the minimum light intensity of 2.5 µW cm −2 , which are at least tenfold greater than those of pristine BPE-PTCDI NW-based ones and comparable to those of high-performance inorganic material-based devices. While a pristine BPE-PTCDI NW-based photodetector is insensitive to the NIR spectral region, the hybrid NW-based phototransistor shows an R of 10.7 A W −1 and EQE of 1.35 × 10 3 % under 980 nm wavelength-NIR illumination. This work demonstrates a viable approach to high-performance photo-detecting systems with broad spectral responsivity.

Photochromic molecules have been recently adopted by many researchers for organic field-effect transistor (OFET) applications, since they offer the opportunity to achieve flexible-type ultraviolet (UV) light sensors with the advantages of organic material-based solution processes. Here, we present the novel usage of an azobenzene derivative in the gate dielectric layer of an OFET for highly sensitive and reliable UV sensing applications. Owing to the large change of capacitance caused by the reversible photoisomerization of azobenzene, the OFET device can modulate efficiently the current signal under UV and visible light. We found that the on-current was greatly amplified upon UV light irradiation with good photoresponsivity and photocurrent ratio and then fully returned to the initial state under visible light. In addition, the device shows a strongly linear relationship with the UV radiation intensity and repetitive on–off response in real-time UV sensing tests, thus being potentially applied in highly sensitive and reliable UV sensors.

Mechanically robust, flexible, and electrically conductive textiles are highly suitable for use in wearable electronic applications. In this study, highly conductive and flexible graphene/Ag hybrid fibers were prepared and used as electrodes for planar and fiber-type transistors. The graphene/Ag hybrid fibers were fabricated by the wet-spinning/drawing of giant graphene oxide and subsequent functionalization with Ag nanoparticles. The graphene/Ag hybrid fibers exhibited record-high electrical conductivity of up to 15,800 S cm−1. As the graphene/Ag hybrid fibers can be easily cut and placed onto flexible substrates by simply gluing or stitching, ion gel-gated planar transistors were fabricated by using the hybrid fibers as source, drain, and gate electrodes. Finally, fiber-type transistors were constructed by embedding the graphene/Ag hybrid fiber electrodes onto conventional polyurethane monofilaments, which exhibited excellent flexibility (highly bendable and rollable properties), high electrical performance (μh = 15.6 cm2 V−1 s−1, Ion/Ioff > 104), and outstanding device performance stability (stable after 1,000 cycles of bending tests and being exposed for 30 days to ambient conditions). We believe that our simple methods for the fabrication of graphene/Ag hybrid fiber electrodes for use in fiber-type transistors can potentially be applied to the development all-organic wearable devices.

Structurally controlled zinc oxide (ZnO) nanorods (NRs) were synthesized for ultraviolet (UV) sensing.

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