scholarly journals Enrichment of Luminescence via Incorporation of Fluxes in La2Zr2O7:Tb3+ Nanophosphors: One Material, Many Possibilities-Latent Fingerprint Visualization, Anti- counterfeiting, Luminescent Flexible Films

2021 ◽  
Author(s):  
D. R. Lavanya ◽  
G. P. Darshan ◽  
J. Malleshappa ◽  
H. B. Premkumar ◽  
S. C. Sharma ◽  
...  
Keyword(s):  
High Performance ◽  
Screen Printing ◽  
Low Cost ◽  
Light Illumination ◽  
Photoluminescence Spectra ◽  
Solution Combustion ◽  
Simple Strategy ◽  
Flexible Films ◽  
Single Material ◽  
Novel Design

Abstract Engineering of single material with multidirectional applications is of crucial for improving the productivity, low cost, flexibility and least power consumption, etc. To achieve these requirements, novel design structures and high performance materials are in urgent need. Lanthanide-doped nanophosphors have greatest strengths and ability in order to tuning its applications in various dimensions. However, nanophosphor applications in latent fingerprints visualization, anti-counterfeiting and luminescent gels/films are still in its infancy. This study demonstrated a simple strategy to enhance the luminescence of Tb3+ doped (1-11 mol %) La2Zr2O7 nanophosphors by conjugating the fluxes via simple solution combustion route. The photoluminescence spectra reveal intense peaks at ~ 491, 546, 587 and 622 nm arises from 5D4◊7FJ (J = 6, 5, 4, 3) transitions of Tb3+ ions, respectively. The highest emission intensity was achieved in the NH4Cl flux assisted nanophosphor as compared to NaBr and NH4F. The colorimetric images of fingerprints visualized using optimized nanophosphor on forensic related surfaces exhibit level –III ridge details, including sweat pores, width of the ridges, bifurcation angle, successive distance between sweat pores, etc. These results are decisive parameters which clearly supports the statement “no two persons have ever been found to have the same fingerprints”. The anti-counterfeiting security ink was formulated using nanophosphor and designed various patterns by simple screen printing and dip pen technology. The encoded information was decrypted only under ultraviolet 254 nm light. All the designed patterns are not just what it looks/feels like and how it works. As a synergetic contribution of enhanced luminescence of the prepared nanophosphor, the fabricated green-emissive films display excellent flexibility, uniformity and transparency in the normal and ultraviolet 254 nm light illumination. Aforementioned results revealed that prepared NH4Cl flux assisted La2Zr2O7: Tb3+(7 mol %) NPs are considered to be best candidate for multi-dimensional applications.

scholarly journals Engineered tunneling layer with enhanced impact ionization for detection improvement in graphene/silicon heterojunction photodetectors

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun Yin ◽  
Lian Liu ◽  
Yashu Zang ◽  
Anni Ying ◽  
Wenjie Hui ◽  
...  
Keyword(s):  
High Performance ◽  
Impact Ionization ◽  
Low Cost ◽  
Atomic Layer ◽  
Light Illumination ◽  
Insulation Material ◽  
Defect States ◽  
Uv Illumination ◽  
Layer Deposition ◽  
The Impact

AbstractHere, an engineered tunneling layer enhanced photocurrent multiplication through the impact ionization effect was proposed and experimentally demonstrated on the graphene/silicon heterojunction photodetectors. With considering the suitable band structure of the insulation material and their special defect states, an atomic layer deposition (ALD) prepared wide-bandgap insulating (WBI) layer of AlN was introduced into the interface of graphene/silicon heterojunction. The promoted tunneling process from this designed structure demonstrated that can effectively help the impact ionization with photogain not only for the regular minority carriers from silicon, but also for the novel hot carries from graphene. As a result, significantly enhanced photocurrent as well as simultaneously decreased dark current about one order were accomplished in this graphene/insulation/silicon (GIS) heterojunction devices with the optimized AlN thickness of ~15 nm compared to the conventional graphene/silicon (GS) devices. Specifically, at the reverse bias of −10 V, a 3.96-A W−1 responsivity with the photogain of ~5.8 for the peak response under 850-nm light illumination, and a 1.03-A W−1 responsivity with ∼3.5 photogain under the 365 nm ultraviolet (UV) illumination were realized, which are even remarkably higher than those in GIS devices with either Al2O3 or the commonly employed SiO2 insulation layers. This work demonstrates a universal strategy to fabricate broadband, low-cost and high-performance photo-detecting devices towards the graphene-silicon optoelectronic integration.

scholarly journals Development of a highly controlled system for large-area, directional printing of quasi-1D nanomaterials

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Adamos Christou ◽  
Fengyuan Liu ◽  
Ravinder Dahiya
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Low Cost ◽  
Large Area ◽  
Sem Images ◽  
Contact Printing ◽  
Controlled System ◽  
Printing System ◽  
Sliding Distance ◽  
Novel Design

AbstractPrinting is a promising method for the large-scale, high-throughput, and low-cost fabrication of electronics. Specifically, the contact printing approach shows great potential for realizing high-performance electronics with aligned quasi-1D materials. Despite being known for more than a decade, reports on a precisely controlled system to carry out contact printing are rare and printed nanowires (NWs) suffer from issues such as location-to-location and batch-to-batch variations. To address this problem, we present here a novel design for a tailor-made contact printing system with highly accurate control of printing parameters (applied force: 0–6 N ± 0.3%, sliding velocity: 0–200 mm/s, sliding distance: 0–100 mm) to enable the uniform printing of nanowires (NWs) aligned along 93% of the large printed area (1 cm2). The system employs self-leveling platforms to achieve optimal alignment between substrates, whereas the fully automated process minimizes human-induced variation. The printing dynamics of the developed system are explored on both rigid and flexible substrates. The uniformity in printing is carefully examined by a series of scanning electron microscopy (SEM) images and by fabricating a 5 × 5 array of NW-based photodetectors. This work will pave the way for the future realization of highly uniform, large-area electronics based on printed NWs.

A high performance and low cost poly(dibenzothiophene-S,S-dioxide)@TiO2 composite with hydrogen evolution rate up to 51.5 mmol h−1 g−1

2020 ◽  
Vol 8 (35) ◽  
pp. 18292-18301
Author(s):  
Ge Shu ◽  
Ye Wang ◽  
Yuda Li ◽  
Song Zhang ◽  
Jia-Xing Jiang ◽  
...  
Keyword(s):  
Visible Light ◽  
Hydrogen Evolution ◽  
High Performance ◽  
Low Cost ◽  
Evolution Rate ◽  
Light Illumination ◽  
Hydrogen Evolution Rate ◽  
Visible Light Illumination

PDBTSO@TiO2-10 exhibited an extremely high HER of 51.5 mmol h−1 g−1 under visible light illumination.

scholarly journals A Novel Phototransistor Device with Dual Active Layers Composited of CsPbBr3 and ZnO Quantum Dots

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1215 ◽  
Author(s):  
Xu Zhang ◽  
Qing Li ◽  
Shikai Yan ◽  
Wei Lei ◽  
Jing Chen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Performance ◽  
Low Cost ◽  
Conducting Layer ◽  
Light Illumination ◽  
High Electron ◽  
Zno Film ◽  
Active Layers ◽  
Zno Qds ◽  
Photodetector Device

Taking advantage of a large light absorption coefficient, long charge carrier diffusion length and low-cost solution processing, all-inorganic halides perovskite CsPbBr3 quantum dots (QDs) are combined with a ZnO QD film to construct a high-performance photodetector. In this work, a novel photodetector device based on transistor structure with dual active layers composed of CsPbBr3 and ZnO film is proposed. In this structure, CsPbBr3 film functions as the light-absorbing layer and ZnO film acts as the conducting layer. Owing to the high electron mobility and hole-blocking nature of the ZnO QDs film, the photo-induced electron-hole pairs can be separated efficiently. As a result, the device exhibits high performance with response of 43.5 A/W, high detection up to 5.02 × 1011 Jones and on/off ratio of 5.6 × 104 under 365 nm light illumination. Compared with the ZnO-only phototransistor (the photodetector with the structure of transistor) the performance of the CsPbBr3 phototransistor showed significant improvement, which is superior to the majority of photodetectors prepared by perovskite. This work demonstrates that the ZnO QDs film can be applied in the photodetector device as a functional conducting layer, and we believe that the hybrid CsPbBr3/ZnO phototransistor would promote the development of low-cost and high-performance photodetectors.

High performance Ni–Fe alloy supported SOFCs fabricated by low cost tape casting-screen printing-cofiring process

2014 ◽  
Vol 39 (34) ◽  
pp. 19747-19752 ◽  
Author(s):  
Kai Li ◽  
Xin Wang ◽  
Lichao Jia ◽  
Dong Yan ◽  
Jian Pu ◽  
...  
Keyword(s):  
High Performance ◽  
Screen Printing ◽  
Low Cost ◽  
Tape Casting

Key role of milling in the optimization of TiO2 nanoinks

2006 ◽  
Vol 21 (6) ◽  
pp. 1561-1569 ◽  
Author(s):  
A. Sanson ◽  
D. Gardini ◽  
G. Montanari ◽  
C. Galassi ◽  
E. Roncari
Keyword(s):  
Rheological Properties ◽  
High Performance ◽  
Screen Printing ◽  
Low Cost ◽  
Intermediate Stage ◽  
Roll Mill ◽  
Transient Network ◽  
Deposited Film

Nanostructured films of TiO2 are becoming more and more attractive as a consequence of their improved sensing properties. Screen printing represents an important low-cost alternative for the production of high-performance devices for the automotive industry. However, to obtain films with superior properties, the composition and each step of the ink production must be carefully controlled. Milling strongly influences the rheological properties of the ink and, as a consequence, the quality of the deposited film. The as-prepared ink was homogenized in a four steps-process with a three-roll mill, and the rheological properties at each intermediate stage were measured. The results showed the dramatic effect of the milling on the flow properties of the nanoink and suggested the importance of a careful control of this step. The rheological behavior of the inks was explained using the basic idea of the transient network theory (TNT) for physically cross-linked networks of polymer solutions. Only an optimized cycle of milling can assure the necessary reproducibility of the ink properties as well as their time stability.

scholarly journals A New 4 × 4 Rectangular Waveguide Short-Slot Coupler in 3D Printed Technology at Ku-Band

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 610
Author(s):  
Raúl V. Haro-Baez ◽  
Jorge A. Ruiz-Cruz ◽  
Juan Córcoles ◽  
José R. Montejo-Garai ◽  
Jesús M. Rebollar
Keyword(s):  
3D Printing ◽  
Rectangular Waveguide ◽  
High Performance ◽  
Low Cost ◽  
Silver Coating ◽  
Compact Structure ◽  
Coupling Region ◽  
3D Printed ◽  
Good Trade ◽  
Novel Design

This paper presents a novel design of an eight-port directional coupler with a very compact structure and simple manufacturing, working in the Ku frequency band. One of the main goals of the design was to ease the manufacturing with a simple structure: the coupler consisted of four rectangular waveguide input ports, four rectangular waveguide output ports, and a central coupling region with only H-plane variation. A prototype was fabricated using additive manufacturing, with a combination of 3D printing and silver coating metallization. The obtained performance showed a theoretical bandwidth of 6.6% with 20 dB return loss for the input/output ports. Good agreement between simulations and measurements was obtained, validating the proposed coupler as a good trade-off for low cost 3D printing, compactness, and high performance for systems requiring a high number of ports as in phase arrays or Butler matrices.

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