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Three-dimensional (3D) cross-linked polymer-like reduced graphene oxide foams (rGOFs) with a seamlessly continuous graphene network, exhibit high photoresponsive and conductivity and have received much attention regarding solar cells and supercapacitors. However, little attention has been paid to photodetection applications of 3D rGOFs. Here we report a novel broadband phototransistor based on metal-3D GFs-metal, which exhibits a high light absorption and a wide spectra response ranging at least from 400 to 1600 nm wavelength with a maximum photoresponsivity of 10 mA/W at 400 nm. In particular, stable and reproducible photocurrent cycles are achieved under different light blue light (405 nm), green light (532 nm), and NIR (808 nm) irradiations. Moreover, the device displays a typical transistor characteristic with a rapid response time of 18 ms at under 532 nm irradiation. The excellent performances indicate 3D rGOF as a promising candidate for future photodetection application. [ABSTRACT FROM AUTHOR]

Abstract As one kind of organic semiconductor materials, Chlorophyll has been attracted great attention with remarkable optical properties. Here, we demonstrate photoresponse and thermoelectric current in the biological Chlorophyll A field effect phototransistors (FEpTs). Meanwhile, it exhibits excellent performances including high responsivity (5 × 103 A/W) and relatively fast response time (rise time ∼ 20.3 s, fall time ∼ 28.2 s) under illumination by 405 nm. Utilizing thermionic emission theory and typical Arrehenius plot, Schottky barrier Φ B is found to be 76.6 meV. The biological phototransistor via low-cost, simple, and scalable fabrication processes opens up new opportunities to realize flexible, transparent organic electronic, and biologically optoelectronic devices. Graphical abstract Image 1 Highlights • Biological transistors based on Chlorophyll exhibit photoelectric and thermoelectric characteristics. • Our devices exhibit excellent performances including high responsivity and relatively fast response time. • Furthermore, based on thermionic emission theory and typical Arrehenius plot, Schottky barrier ϕ B is found to be 76.6 meV. • The biological phototransistors are fabricate through low-cost, simple, and scalable fabrication processes. • It opens up new opportunities to realize flexible, transparent organic electronic, and biologically optoelectronic devices. [ABSTRACT FROM AUTHOR]

Here we present a feasible way to fabricate a high-performance graphene phototransistor functionalized with Poly(3-hexylthiophene) (P3HT)/graphene bulk heterojunction by solution processing, which possesses the advantages of the high carrier mobility of graphene and the high visible light absorption of P3HT. The hole field-effect mobility for the device was 3.8 cm 2 V − 1 s −1 at room temperature. The photoresponsivity, external quantum efficiency and detectivity were 12 A/W, 3 × 10 3 % and 1.6 × 10 6 Jones at a illumination irradiance of 15 mW/cm 2 respectively. The phototransistor exhibited sensitive photoresponse with a rise time of 168 ms and a decay time of 121 ms. [ABSTRACT FROM AUTHOR]

Abstract Methylammonium lead halide perovskites have received substantial attention in the research photovoltaic communities, because of excellent optoelectronic properties, including long electron-hole diffusion distance, large absorption coefficients in the UV–Vis spectral region, low-cost, solution-based processing and low binding energy of exciton. However, the crystal defects of perovskite films such as pinholes, defect and grain boundaries lead to carrier capture, trapping and scattering, so that reduce carrier mobility in the channel, which has become the bottleneck of high device performance and limited the application in photo detection. Here we report a simple and straightforward strategy based on a multi-step annealing process, which can effectively improves the coverage, smoothness, uniformity and crystallinity by restraining defects of pinhole formation. The field-effect mobilities of perovskite photodetector treated by one-step (OS) direct annealing method at room temperature shows mobility as 0.256 (0.129) cm2V−1s−1 for holes (electrons), which increase to 2.32 (1.18) cm2V−1s−1 for that treated by muti-step (MS) annealing method. The latter exhibits high figure of merit as detectivity of 8.94 × 1011 Jones, a responsivity of 32 A/W and a short response time of 42 μs. Moreover, it shows better stability with polymethylmethacrylate film covered, which can maintain 90% of initial performance for 10 days in ambient air. These findings demonstrate that MS annealing methods is simple yet effective and feasible to prepared high-efficient perovskite based photo detectors. Highlights • As well-known, the crystal defects of perovskite films such as pinholes, defect and grain boundaries lead to carrier capture, trapping and scattering, so that reduce carrier mobility in the channel, which has become the bottleneck of high device performance and limited the application in optoelectric devices. • However, the most works focused on perovskite solar cells, ignoring other perovskite optoelectric devices, like phototransistors. • Here we report a simple and straightforward strategy based on a multi-step annealing process, which can effectively improves the coverage, smoothness, uniformity and crystallinity by restraining defects of pinhole formation. • The field-effect mobilities of perovskite photodetector treated by one-step (OS) direct annealing method at room temperature shows mobility as 0.256 (0.129) cm2V−1s−1 for holes (electrons), which increase to 2.32 (1.18) cm2V−1s−1 for that treated by muti-step (MS) annealing method. • The latter exhibits high figure of merit as detectivity of 8.94 × 1011 Jones, a responsivity of 32 A/W and a short response time of 42 μs. Moreover, it shows better stability with polymethylmethacrylate film covered, which can maintain 90% of initial performance for 10 days in ambient air. [ABSTRACT FROM AUTHOR]