Taiwan University Chen Weng Adv. Mater. Technol.: Photonic transistor memory based on 1D electrospinned semiconductor polymer/perovskite composite nanofiber
DOI: 10.1002/admt.202100080
Compared with traditional voltage-driven memory devices, photonic field effect transistor (FET) memory devices have unique advantages such as contactless programming capabilities, fast data transmission and low power consumption. This paper reports for the first time a photon FET memory device consisting of only nanofibers. Polythiophene embedded in perovskite nanocrystals (βNCs) is used as a one-dimensional semiconductor channel for nanofiber matrix. The on/off current ratio of the optimal device is approximately 103 and the data retention time exceeds 104 s, which can be attributed to the favorable energy level arrangement and molecular accumulation of conjugated polymers in the nanofibers. The composite nanofiber system exhibits excellent photoresponsiveness and charge retention, and the composite system has better performance than film-based counterparts due to its regular one-dimensional confined structure and well-dispersed βNCs. Overall, the fine-tuned conjugated polymer and one-dimensional confined structure in nanofibers ensure good data discrimination and highly fault-tolerant photonic memory devices. Furthermore, fiber-based flexible memory devices have excellent photonic storage performance, indicating their integrity in applications in wearable electronics. This system applies one-dimensional perovskite nanocrystalline/conjugated polymer composite nanofibers to high-performance photonic memory devices for the first time, revealing the huge potential of composite nanostructures in new groundbreaking photonic devices.
Figure 1. Schematic diagram of the preparation process of coaxial electrospinning system and directional coaxial nanofibers, composed of conjugated polymer-perovskite NCs composite material and PEO as core and shell respectively.
Figure 2.a) XRD spectrum of perovskite nanocrystal powder with surfactants including octanylamine and β-CD was added. b) FTIR spectra of pure β-CD and perovskite nanocrystals.
Figure 3.a) TEM image of coaxial electrospinning composite RP-17/βNC nanofibers. b) TEM image of core RP-17/βNC nanofibers after removal of PEO shell, with a scale of 0.2 µm.
Figure 4.a) Schematic diagram of nanofiber-based photonic transistor memory. b) Time IDS curve of composite nanofiber-based photonic transistor memory running at VDS=-60V. c) Energy map of nanofiber perovskite nanocrystals (βNC) and polythiophene charge transport medium. d) Long-term stability of RP-17/βNC composite nanofibers within 14000s after 120s of light writing. The illustration shows leakage current after multiple optical programming and electrical erase cycles.
Figure 5. 2D grazing incident X-ray diffraction (2D GIXD) diagram of composite perovskite nanocrystalline nanofibers composed of RP-17 composite materials (the designated crystal planes of polythiophene and perovskite nanocrystalline are represented in blue and black fonts, respectively). b) Full window 1D grazing incident X-ray diffraction (1D GIXD) diagram of various composite nanofibers. c) Azimuth analysis of (100) layered stacking of various composite nanofibers. 2D-GIXD diagram of oriented nanofibers when incident light is parallel (d) and perpendicular (e) to the fiber axis. f) Schematic diagram of polymer stacking in composite nanofibers (red lines represent the direction of the polymer backbone in yellow conjugated polymer medium), while exposed to incident beams of different orientations based on the fiber axis. (The specified crystal planes of polythiophene and perovskite nanocrystals are represented in red and white fonts respectively)
Figure 6.a) Photonic transistors using RP-17-based composite nanofibers are photoprogrammed at different optical programming times, and the time IDS curve when VDS=-60V is used. b) Light illumination within 10 s for 1 s, and short-pulse photoprogramming of photonic transistors using RP-17-based composite nanofibers. c) Comparison of the time IDS curves of photonic transistors using RP-17-based composite nanofibers and thin films at VDS=-60V. d) The photoresponsiveness, time constant and memory window changes of composite RP-17/βNC nanofibers and films studied.
Figure 7.a) Structure and photographs of a fiber-based flexible photonic memory composed of polyimide as a dielectric and substrate. b) Time IDS curve of the flexible device before and after 100 cycles of convex/concave bends.
Article source: Yisibang //www.espun.cn/
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