Visible Light Transparency Research Articles

Dipping-Press Coating Method for Retaining Transparency and Imparting Hydrophobicity Regardless of Plastic Substrate Type.

Plastics are used in cover substrates for billboards, windows, large LED signboards, lighting devices, and solar panels because they are transparent and can be colored and shaped as desired. However, when plastic cover substrates installed in outdoor environments are constantly exposed to harsh conditions such as snow, rain, dust, and wind, their transparency deteriorates owing to watermarks and dust contamination. Herein, we investigated a simple dipping-press coating method that can impart hydrophobicity while maintaining the transparency, regardless of the plastic substrate type. A highly transparent and hydrophobic coating film was formed on a plastic substrate by a two-step process, as follows: (1) application of a polydimethylsiloxane–octadecylamine coating by a dipping process, and (2) embedding (1H,1H,2H,2H-heptadecafluorodec-1-yl) phosphonic acid–aluminum oxide nanoparticles by a thermal press process. The plastic substrates on which the highly transparent and hydrophobic coating film was formed showed 150° or higher hydrophobicity and 80% or higher visible light transparency. The coating method proposed herein can easily impart hydrophobicity and is compatible with any plastic substrate that must maintain prolonged transparency without contamination when exposed to adverse conditions.

Thermoplastic Polymeric Materials for Spacecraft Applications: Flame Retardant Properties and UV/AtOx Aging Analysis

Space-mission development introduced the problem of human isolation in extreme environments. The integration of architectural concepts such as windows, with their technical implications into human space missions, is necessary especially for long-duration space flights. Such solutions must be subjected to close certification testing in order to establish their compliance with severe space environment conditions. Moreover, projects of long-term missions involve a renewed concern about fire safety in manned space vehicles. The supposed occupancy time of the order of decades, in fact, makes unplanned fire ignition events virtually unavoidable. An experimental test-plan performed to qualify a commercial thermoplastic material for applications as transparent element in spacecraft is reported in the present work. A flame exposure test, as well as ultraviolet radiation and atomic oxygen erosion rate measurements, was carried out on a commercial poly-sulfone material, following ASTM standard procedures. The aim of the research was to develop and put forward flame retardant structures able to withstand the harsh space environment, preventing or mitigating the degradation of their physical and chemical integrity, with particular regard to the visible-light transparency. The results obtained show that the tested poly-sulfone may be considered as a promising material for the claimed application, even if further surface optimization treatments should be conceived in order to gain a full adaptability to the operative constraints.

Flexible transparent solar blind ultraviolet photodetector based on amorphous Ga<sub>2</sub>O<sub>3</sub> grown on mica substrate

Solar-blind deep-ultraviolet (UV) photodetectors (PDs) based on the super-wide bandgap semiconductor material Ga<sub>2</sub>O<sub>3</sub> is one of the hot topics of current research, but how to prepare high-performance Ga<sub>2</sub>O<sub>3</sub>-based solar-blind PDs in the field of flexible and transparent optoelectronics still faces challenges. In this work, an amorphous Ga<sub>2</sub>O<sub>3</sub> film with high transmittance is grown on a flexible mica substrate by using the radio frequency magnetron sputtering technology. On this basis, using AZO as an electrode material, a transparent metal-semiconductor-metal (MSM) structured solar-blind deep ultraviolet photodetector based amorphous Ga<sub>2</sub>O<sub>3</sub> film is fabricated, and the performance of PD in the planar state and after multiple bending are systematically compared and analyzed. The results show that the amorphous Ga<sub>2</sub>O<sub>3</sub> based transparent PD has ultra-high visible light transparency and shows good solar-blind ultraviolet photoelectric characteristics. The responsivity of the PD under 254 nm light is 2.69 A/W, and the response time and the recovery time are 0.14 s and 0.31 s, respectively. After bending 300 times, the PD has a photoresponse behavior similar to its planar state, and the performance of the PD has no obvious attenuation phenomenon, showing good flexibility and stability. This work proves that AZO can be used as the electrode material of the next generation of flexible and visible light transparent Ga<sub>2</sub>O<sub>3</sub> based photodetectors, and provides a reference for developing the high-performance flexible and transparent solar-blind deep ultraviolet photodetectors.

Enhanced Performance of a VLC and ULEAPS Fiber Seamless Integrated System Employing Novel Weighted Pre-FDE)

We reported and experimentally demonstrated a 1 Gbit/s guided visible light transparent based on weighted pre frequency domain equalization (Pre-FDE) and post time domain equalizer over a 100 m ULEAPS fiber. The experimental results verified the effectiveness and improvement of the proposed method comparing with the traditional post-equalizers. To the best of our knowledge, this is the highest data rate ever achieved in a VLC transparent employing a commercially available blue LED.

One-step fabrication of transparent superhydrophobic surface

A self-cleaning, transparent superhydrophobic silica-based surface with water contact angle (CA)/sliding angle (SA) 168°/2° was fabricated by simple one-step thermal oxidation of silicone grease. Microstructural studies (FESEM/TEM) confirmed the presence of a sponge-like pore structure of amorphous silica nanoparticle having a diameter of around 20 ± 2.2 nm. EDS analysis confirms the presence of C, Si, and O in coated substrates. Also, phase and thermal studies (XRD, FTIR, and TG-DSC) analysis showed the thermo-oxidative decomposition of silicone grease results in superhydrophobic –H2C-Si-O-Si-CH2- network structure at 400 °C followed by thermally stable superhydrophilic HO-Si-O-Si-OH network structure at 500 °C. The coated surface showed excellent stability towards corrosive liquids (1 M NaCl, NaOH, HCl aqueous solution, and hot water) and exposed temperature up to 400 °C. The maximum visible light transparency of the superhydrophobic glass was 92.4% compared to the uncoated glass (93.3%). Thus, making transparent superhydrophobic surfaces by a simple and straightforward process can be potentially used in self-cleaning glasses for various engineering applications.

Minimization of Optical Losses in Colorful Semitransparent Organic Solar Cells Using Antimony Oxide Cavity-Based Fabry-Pérot Etalon Electrodes

Semitransparent organic solar cells (STOSCs) are a technology that combines the benefits of visible light transparency and light-to-electrical energy conversion. One of the greatest opportunities for STOSCs is their integration into windows and skylights in energy-sustainable buildings. For this application, the aesthetic aspects of solar cells may be as important as their electrical performance. Here, our strategy enables to achieve high-quality and colorful STOSCs using Fabry-Pérot etalon-type electrodes. These electrodes are composed of an antimony oxide (Sb2O3) cavity layer and two thin Ag mirrors. These dichroic tri-layer structures perform two functions as top conducting electrodes and color filters. The electrodes are fabricated by thermal evaporation of smooth sheets of Ag and metal oxide thin films, with appropriate thicknesses calculated by the transfer matrix methodology. In this manner, dichroic electrodes with a high spectral purity were achieved with transmission wavelengths that could be accurately tuned throughout the visible spectrum by varying the Sb2O3 cavity thickness. These dual-function electrodes were applied to photovoltaic devices and displayed vivid colors, natural transparency, and good performance as compared to devices that use conventional metal electrodes. Furthermore, to achieve saturated colors and low photocurrent losses, active layer materials were selected such that their transmission peaks matched the transmission maxima of the electrodes. These strategies for colorful STOSCs resulted in power conversion efficiencies (PCEs) of up to 12.1% and maximum transmittances (T MAX) of 22.5% in blue devices, PCEs of up to 9.71% and T MAX of 35.4% in green devices, and PCEs of up to 7.63% and T MAX of 34.7% in red devices.

High-performance and stable inverted perovskite solar cells using low-temperature solution-processed CuNbOx hole transport layer

For a typical perovskite solar cell (PSC), the hole transport layer (HTL) plays a vital role in determining device performance and stability. Herein, for the first time, we demonstrate that a low-temperature solution-processed copper-niobium oxide (CuNbOx) thin film, consisting of CuNbO3 and CuNb2O6 phases, can serve as an efficient HTL to develop PSCs with high-performance and long-term stability simultaneously. The CuNbOx thin film possesses high optical transparency in visible light, well-matched energy levels with perovskite, and excellent hole extraction capability from the perovskite layer. By optimizing the precursor concentration, the CuNbOx-based device reaches the best power conversion efficiency (PCE) of 16.01% with negligible hysteresis. In comparison, the control device based on the extensively studied PEDOT:PSS HTL shows an obviously lower PCE of 10.13%. Besides exhibiting significant improvement in photovoltaic performance, our CuNbOx-based device also shows much enhanced long-term stability than the control device. After 1000 h of storage in air without encapsulation, the CuNbOx-based PSCs maintains ~78% of their initial efficiency, whereas the PCE of PEDOT:PSS-based PSCs drops to ~44% of the initial value. Overall, this study suggests that the utilization of the inorganic CuNbOx thin film as the HTL provides a novel route for fabricating low-cost, high-performance, and stable PSCs.

Single-Crystalline All-Oxide α-γ-β Heterostructures for Deep-Ultraviolet Photodetection.

Recent advancements in gallium oxide (Ga2O3)-based heterostructures have allowed optoelectronic devices to be used extensively in the fields of power electronics and deep-ultraviolet photodetection. While most previous research has involved realizing single-crystalline Ga2O3 layers on native substrates for high conductivity and visible-light transparency, presented and investigated herein is a single-crystalline β-Ga2O3 layer grown on an α-Al2O3 substrate through an interfacial γ-In2O3 layer. The single-crystalline transparent conductive oxide layer made of wafer-scalable γ-In2O3 provides high carrier transport, visible-light transparency, and antioxidation properties that are critical for realizing vertically oriented heterostructures for transparent oxide photonic platforms. Physical characterization based on X-ray diffraction and high-resolution transmission electron microscopy imaging confirms the single-crystalline nature of the grown films and the crystallographic orientation relationships among the monoclinic β-Ga2O3, cubic γ-In2O3, and trigonal α-Al2O3, while the elemental composition and sharp interfaces across the heterostructure are confirmed by Rutherford backscattering spectrometry. Furthermore, the energy-band offsets are determined by X-ray photoelectron spectroscopy at the β-Ga2O3/γ-In2O3 interface, elucidating a type-II heterojunction with conduction- and valence-band offsets of 0.16 and 1.38 eV, respectively. Based on the single-crystalline β-Ga2O3/γ-In2O3/α-Al2O3 all-oxide heterostructure, a vertically oriented DUV photodetector is fabricated that exhibits a high photoresponsivity of 94.3 A/W, an external quantum efficiency of 4.6 × 104%, and a specific detectivity of 3.09 × 1012 Jones at 250 nm. The present demonstration lays a strong foundation for and paves the way to future all-oxide-based transparent photonic platforms.

Enhanced stability of silver nanowire transparent conductive films against ultraviolet light illumination

Silver nanowires are susceptible to degradation under ultraviolet (UV) light illumination. Encapsulating silver nanowire transparent conductive films (AgNW TCFs) with UV shielding materials usually result in the increasing of the sheet resistance or the decrease of the visible light transparency. Herein, we combine a reducing species (FeSO4) and a thin layer (overcoating) of UV shielding material to solve the stability and the optical performance issues simultaneously. The AgNW TCFs show excellent stability under continuous UV light illumination for 14 h, and their sheet resistance varies only 6%. The dramatic enhancement of the stability against UV light illumination for as-obtained TCFs will make them viable for real-world applications in touch panels and displays.

Control of Optical Absorption and Emission of Sputtered Copper Iodide Thin Films

Optical absorption and emission spectra are the important quantifiable properties for CuI as a promising optoelectronic material. Previous research on the sputter deposition of CuI focuses on room‐temperature growth. Herein, the effect of growth temperature on the selected optical features of sputtered CuI thin films is investigated. An enhanced visible light transparency and a steeper absorption edge are achieved for CuI thin films by optimizing the growth temperature. The PL intensity ratio of free exciton to defect‐related emission increases with increasing substrate temperature. These results suggest a strategy of growth temperature optimization for the enhanced absorption and emission of CuI for advanced optoelectronic applications.

A visible-light-transparent camouflage-compatible flexible metasurface for infrared–radar stealth applications

A visible-light-transparent metasurface has been designed to achieve infrared (IR)–radar stealth. An optically transparent material, indium tin oxide was chosen in preference to other low-IR-emissivity metals to achieve camouflage compatibility for the IR–radar stealth material. In addition, flexible polyethylene terephthalate was adopted as the dielectric material to in order to benefit from its visible light transparency; its softness could also improve its application prospects. The fabricated structure exhibited a strong absorptivity of over 90% from 8.265 GHz to 17.65 GHz and a low IR emissivity of less than 0.3 in the region of 3–14 μm. The results demonstrated that the metasurface was polarization independent and it was still able to maintain 90% of its absorptivity with an oblique incidence of 20°. The good consistency between the experimental and simulated results verified that the proposed metasurface can be practically applied in multifunctional stealth technology.

Drug-loaded and Blue-ray Filtered Hydrogel as a Potential Intraocular Lens for Cataract Treatment.

Indomethacin (IND) is a class of non-steroidal, anti-inflammatory drugs, which is used to treat various kinds of ocular inflammation, and has been reported to prevent posterior capsule opacification (PCO) by inhibiting the mitosis and collagen synthesis of human lens epithelial cells (LECs). In addition, the specific absorption spectrum of indomethacin shows the effect of absorbing short-wavelength blue-violet light. We prepared an indomethacin-loaded hydrogel as a potential intraocular lens (IOLs) material to prevent endophthalmitis, PCO and filter harmful blue light. Indomethacin prodrugs (HEMA-IND) (HI) were prepared by esterification of indomethacin and 2-hydroxyethyl methacrylate (HEMA), and poly (HEMA-co-MAA-co-MMA-co- HI) (HAMI) hydrogels were prepared by free-radical polymerization of 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), methacrylic acid (MAA) and HI. The physical and chemical properties of obtained hydrogel were detected, including optical, morphology, thermomechanical and surface properties, equilibrium water content, drug release behaviors and cytotoxicity. HAMI hydrogels can filter harmful short-wavelength blue light and show other necessary properties like visible light transparency, glass transition temperatures, mechanical strength, and biocompatibility for making intraocular lenses. Meanwhile, MAA increases the hydrophilicity of the hydrogels, resulting in a lower water contact angle and controllable drug release from the hydrogels. In summary, HAMI hydrogels show a great potential as IOL biomaterials that can maintain the sustained release of indomethacin and filter harmful blue light after cataract surgery. Lay Summary: People with cataract surgery can be at high risk of postoperative complications, such as PCO and postoperative endophthalmitis. Moreover, early IOLs allowed all ultraviolet (UV) and visible light to pass through retina without restriction, thus to damage the retina and the retinal pigment epithelium, which may lead to retinopathy and age-related macular degeneration (AMD). Herein, we sought to design and prepare a kind of IOLs loaded with indomethacin to mitigate those postoperative complications and filter harmful blue light to improve the treatment prognosis.

Mechanism for transmittance light tunable property of nanocrystalline Eu-doped SmB6: Experimental and first-principles study

Binary nanocrystalline rare-earth hexaboride is regarded as one of the promising optical absorption materials that possess the high transparency for visible light and the strong absorption for NIR due to the effects of localized surface plasmon resonance. In present work, we experimentally investigated the structural and optical absorption of ternary nanocrystalline Eu-doped SmB6 powder. As a result, it is found that the reaction temperature as an important factor not only refines the grain size, but also improves the powder dispersion of synthesized samples. The optical absorption results reveal that the transmittance wavelength of nanocrystalline SmB6 increases from 696 nm to exceeding 1000 nm with the Eu doping content increasing to x = 0.8. Theoretically, in order to study the transmittance wavelength tunable mechanisms of nanocrystalline Eu-doped SmB6, the electronic structure, density of states and energy loss function were calculated by first-principle calculation. It shows that the Eu2+ doping into SmB6 effectively reduces the plasma frequency excitation energy from 1.48 to 1.25 eV and leads to the transmittance wavelength redshift toward a higher wavelength. Based on above meaningful studies, present work is helpful for extension of optical applications of nanocrystalline SmB6 powder.

Thermal evolution of point defects in indium doped ZnO transparent conducting films

High visible light transparency and conductivity of ZnO enable the use of its material as transparent conducting films, in which point defects are vitally important for determining its optoelectronic properties. Herein, Indium doped ZnO thin films (ZnO:In) were prepared by radio-frequency magnetron sputtering technique. Thermal evolution of point defects and their effects on the microstructure and photoelectric properties of ZnO:In transparent conducting films were systematically investigated. The results show that thermal annealing induces the dissociation of extensive zinc interstitial clusters, causing their concentration gradually decreasing with increasing annealing temperature. Furthermore, when annealing at low temperature (≤ 500°C), the concentration of oxygen vacancy and zinc vacancy defects also decreases with increasing temperature. However, after annealing at higher temperature (600 and 700°C), additional vacancy defects are generated due to the evaporation of zinc and oxygen atoms from the film surface. It is demonstrated that the evolution of point defects caused by thermal annealing directly affects the microstructure and photoelectric properties of ZnO:In transparent conducting films.

Facile fabrication of KmCsnWO3 with greatly improved near-infrared shielding efficiency based on W5+-induced small polaron and local surface plasmon resonance (LSPR) modulation

Cesium tungsten bronze (CsxWO3) has potential applications in the field of energy-saving window glasses due to its visible light transparency and near-infrared (NIR) shielding ability. In order to further improve the NIR shielding performance and realize low-cost large-scale production of tungsten bronze, in this work, K, Cs co-doped tungsten bronze (KmCsnWO3, m + n = 0.32) were fabricated by facile solid-state reaction method. It has been clarified that K, Cs co-doping could promote the formation of W5+ and thus enhance the localized surface plasmon resonance (LSPR). Moreover, the K, Cs co-doping is conducive to the formation of single or double bond between W5+ and O, and the double bond W5+=O can increase the strength of small polaron effect and greatly improve the NIR shielding at wavelength 730–1100 nm. Particularly, when K:Cs (mol) = 0.2:0.8, the maximum visible light transmittance of 66.89% and near-infrared shielding rate of 98.25% could be achieved respectively. This work is of great significance for developing CsxWO3 tungsten bronze with improved NIR shielding performance and realizing its industrial production and practical applications in the field of energy-saving windows.

Optically-switchable thermally-insulating VO2-aerogel hybrid film for window retrofits

Developing easy-to-install energy-efficient window retrofitting materials is important for reducing the heating and cooling loads of buildings. However, it is very challenging to achieve window retrofits that are simultaneously thermally insulating, visible-light transparent, and dynamically switchable in solar transmission. Here, a visibly transparent and thermally insulating film was proposed to reduce the energy loss through windows. By embedding insulator–metal phase transition vanadium dioxide (VO2) nanoparticles inside an ultralow thermal conductivity aerogel film, the thermal insulation performance is greatly improved in such thermochromic film while the solar transmission can be dynamically switched in response to ambient conditions. A coupled heat conduction and solar radiation heat transfer model was developed to evaluate the effect of geometric features such as film thickness, nanoparticle size, and concentration on the thermal and optical performance of the proposed films. It was shown that a 3.0 mm thick film could achieve a low U-value of ~ 3.0 W/(m2K), and a high luminous transmittance of > 60% and a solar modulation ability of ~ 20%. This film improves the performance of single-pane windows by reducing the energy loss, improving thermal comfort, and avoiding moisture condensation in cold climates and overheating in hot climates.

Preparation and Optical Absorption Properties of Ternary Rare Earth Boride LaxPr1-xB6 Submicron Powders.

As multifunctional materials, rare-earth hexaborides (RB6) display many interesting physical properties such as optical absorption, magnetic and thermionic emission. With the wide application of rare earth hexaboride and the continuous extension of its research fields, researchers have studied the synthesis of multi-rare earth hexaboride nano-powders and their thermal emission and light absorption properties. In the present work, ternary Single-phase LaxPr1-xB6 submicron powders are successfully synthesized using a solid-state reaction, in which lanthanum chloride (LaCl₃) and praseodymium chloride (PrCl₃) are used as rare-earth source and NaBH₄ as the boron source under continuous vacuum conditions. The reaction temperature is 1150 °C and the holding time is 2 h. The Pr doping effects on crystal structure, grain morphology, and optical absorption properties were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and ultraviolet-vis absorption measurements. The XRD patterns show that the diffraction peaks are sharp and well-defined, and no other extra impurity peaks were detected, indicating the characteristics of well-crystallized materials. It is found that all the LaxPr1-xB6 solid powders are of single phase. The SEM results demonstrate that the cubicshaped ternary LaxPr1-xB6 submicron crystals with a size of 50~200 nm are obtained. The TEM images reveal the cubic single-crystalline nature, and the FFT patterns implies the lattice fringe d = 0.416 nm which agrees well with the (100) crystal plane. The elements mapping results indicates that the Pr atoms occupied the lattice sites of LaB6. The optical absorption results show that the absorption valley of LaB6 are located at 591 nm. With the increase of Pr doping contents from 0.2 to 0.8, the absorption valley moves from 596.3 nm to 612.9 nm, indicating the characteristics of visible light high transparency. The first-principle calculation results manifest that the move of the absorption valley of LaB6 in the visible region after doping Pr is related to the decrease of kinetic energy of electrons near the Fermi plane. X-ray photoelectron spectroscopy (XPS) analysis shows that the La and Pr exist in the type of La3+ and Pr3+ in LaxPr1-xB6. Therefore, it exists as an efficient optical absorption material. The LaxPr1-xB6 should open up a new route to extend the optical applications of rare-earth hexaborides.

Aesthetic and colorful: Dichroic polymer solar cells using high-performance Fabry-Pérot etalon electrodes with a unique Sb2O3 cavity

Abstract Semitransparent organic solar cells (STOSCs) are a technology that combines the benefits of visible light transparency and light-to-electrical energy conversion. One of the greatest opportunities for STOSCs is their integration into windows and skylights in energy-sustainable buildings. For this application, the aesthetic aspects of solar cells may be as important as their electrical performance. Here, our strategy enables to achieve high-quality and colorful STOSCs using Fabry-Perot etalon-type electrodes. These electrodes are composed of an antimony oxide (Sb2O3) cavity layer and two thin Ag mirrors. These dichroic tri-layer structures perform two functions as top conducting electrodes and color filters. These dual-function electrodes were applied to photovoltaic devices and displayed vivid colors, natural transparency, and good performance as compared to devices that use conventional metal electrodes. Furthermore, to achieve saturated colors and low photocurrent losses, active layer materials were selected such that their transmittance peaks matched the transmittance maxima of the electrodes. These strategies for colorful STOSCs result in power conversion efficiencies (PCEs) of up to 13.3% and maximum transmittances (TMAX) of 24.6% in blue devices, PCEs of up to 9.71% and TMAX of 35.4% in green devices, and PCEs of up to 7.63% and TMAX of 34.7% in red devices.

A transparent robust quasi‐isotropic circularly polarized antenna for Cub‐Sat and outdoor wireless

AbstractIn this article, a highly robust antenna is proposed for omnidirectional circular polarized communications in harsh environments at 2.45 GHz industrial, scientific, and medical frequency band. Circular polarization is realized by utilizing a combination of two magnetic and electric dipoles. The proposed antenna is based on a transparent structure and covered by a quarter wavelength thick layer of plexiglass to achieve desired robustness and visible light transparency. Meanwhile, because of the high transparency of the glass, it can integrate with solar cells to simultaneously propagate signals and harvest energy. The average gain and bandwidth of the antenna are 1.7 dBic and 300 MHz, respectively. The antenna's axial ratio is achieved less than 3 dB within the bandwidth, showing circular polarization behavior. The proposed compact antenna is numerically and experimentally analyzed and the results have a great agreement. In another viewpoint, the structure delivers promising possibilities to improve the propagating and radiating properties, which bring in significant advantages for real‐world multifunctional applications.

Broad Bandwidth, Self-Powered Acoustic Sensor Created by Dynamic Near-Field Electrospinning of Suspended, Transparent Piezoelectric Nanofiber Mesh.

Freely suspended nanofibers, such as spider silk, harnessing their small diameter (sub-micrometer) and spanning fiber morphology, behave as a nonresonating acoustic sensor. The associated sensing characteristics, departing from conventional resonant acoustic sensors, could be of tremendous interest for the development of high sensitivity, broadband audible sensors for applications in environmental monitoring, biomedical diagnostics, and internet-of-things. Herein, a low packing density, freely suspended nanofiber mesh with a piezoelectric active polymer is fabricated, demonstrating a self-powered acoustic sensing platform with broad sensitivity bandwidth covering 200-5000 Hz at hearing-safe sound pressure levels. Dynamic near-field electrospinning is developed to fabricate in situ poled poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) nanofiber mesh (average fiber diameter ≈307 nm), exhibiting visible light transparency greater than 97%. With the ability to span the nanomesh across a suspension distance of 3 mm with minimized fiber stacking (≈18% fiber packing density), individual nanofibers can freely imitate the acoustic-driven fluctuation of airflow in a collective manner, where piezoelectricity is harvested at two-terminal electrodes for direct signal collection. Applications of the nanofiber mesh in music recording with good signal fidelity are demonstrated.