Flexible Transparent and Free‐Standing SiC Nanowires Fabric: Stretchable UV Absorber and Fast‐Response UV‐A Detector

Abstract

Transparent and flexible materials are desired for the construction of photoelectric multifunctional integrated devices and portable electronics. Herein, 2H-SiC nanowires are assembled into a flexible, transparent, self-standing nanowire fabric (FTS-NWsF). The as-synthesized ultralong nanowires form high-quality crystals with a few stacking faults. The optical transmission spectra reveal that FTS-NWsF absorbs most incident 200-400 nm light, but remains transparent to visible light. A polydimethylsiloxane (PDMS)-SiC fabric-PDMS sandwich film device exhibits stable electrical output even when repeatedly stretched by up to 50%. Unlike previous SiC nanowires in which stacking faults are prevalent, the transparent, stretchable SiC fabric shows considerable photoelectric activity and exhibits a rapid photoresponse (rise and decay time < 30 ms) to 340-400 nm light, covering most of the UV-A spectral region. These advances represent significant progress in the design of functional optoelectronic SiC nanowires and transparent and stretchable optoelectronic systems.

Compositional and structural engineering of inorganic nanowires toward advanced properties and applications

“…Among various polytypes, 2H‐SiC nanowires possessing a large bandgap (~ 3.3 eV) are expected to be fabricated into deep violet light detectors. Sun et al synthesized Al‐O‐codoped high‐quality 2H‐SiC nanowires free of intense stacking faults, which were then assembled into a flexible and transparent nanowire film (Figure A‐D) . A UV‐A detector with a targeted wavelength of 340‐400 nm was accordingly achieved, which delivered a rapid switching‐on process (rise time < 30 ms).…”

“…D, Time response under the excitation of a 375‐nm continuous laser. Reproduced with permission . Copyright 2018, Wiley‐VCH.…”

“…As a structural protection layer and electrical shielding, SiO 2 and Al 2 O 3 have been frequently applied as nanowire shells . Additionally, all of these operations result in changed mechanical performance, that is, modified Young's modulus, fracture strength, maximum strain, nonlinear elasticity, viscoelasticity, and so on, which has stimulated fundamental research and largely expanded their application in fields such as nano electro mechanical system (NEMS) and flexible (wearable) devices …”

“…For instance, through control of the vacancy distribution, singlephoton emission could be realized in some materials, 32,33 while a macroscopic property change (ie, enhanced conductivity, varied light emission, modified mechanical behavior, improved sensor performance, and so on) could be obtained in most semiconductor nanowires. [34][35][36][37][38][39] In nanowires with heterojunctions, a specific built-in electric field in the depletion region could be constructed by rationally matching the energy band diagrams, which largely determines the carrier behavior in binary systems, that is, injection into the host nanowire, formation of a 1D electron (hole) gas in the confined region, and so on. When working in the sensor mode, such nanowires display interesting tunable performance.…”

Silver Telluride Nanowire Assembly for High‐Performance Flexible Thermoelectric Film and Its Application in Self‐Powered Temperature Sensor

“…Our tests are divided into two procedures: the first test studies the electric resistance behavior when bending, and the second test consists of a cycling mechanical test to evaluate the long-term effect of continuous bending over the electric resistance. [23] An important application of the Ag 2 Te nanowire thermoelectric generator is working as a self-powered temperature sensor. In contrast, owing to its brittleness, the sheet resistance of a commercial indiumtin oxide electrode on polyethylene terephthalate (ITO@PET) increases with bending angle and dramatically elevates at the bending angle above 120°.…”