Evaluation of a Multicommuted Flow System for Photometric Environmental Measurements

A portable flow analysis instrument is described for in situ photometric measurements. This system is based on light-emitting diodes (LEDs) and a photodiode detector, coupled to a multipumping flow system. The whole equipment presents dimensions of25 cm×22 cm×10 cm, weighs circa 3 kg, and costs 650 €. System performance was evaluated for different chemistries without changing hardware configuration for determinations of (i)Fe3+withSCN-, (ii) iodometric nitrite determination, (iii) phenol with sodium nitroprusside, and (iv) 1-naphthol-N-methylcarbamate (carbaryl) withp-aminophenol. The detection limits were estimated as 22, 60, 25, and 60 ngmL-1for iron, nitrite, phenol, and carbaryl at the 99.7% confidence level with RSD of 2.3, 1.0, 1.8, and 0.8%, respectively. Reagent and waste volumes were lower than those obtained by flow systems with continuous reagent addition. Sampling rates of 100, 110, 65, and 72 determinations per hour were achieved for iron, nitrite, phenol, and carbaryl determinations

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A Compact Microcontrolled Microfluidic System for Photometric Determination of Phosphate in Natural Water Samples

Australian Journal of Chemistry ◽

10.1071/ch14602 ◽

2015 ◽

Vol 68 (7) ◽

pp. 1108 ◽

Cited By ~ 2

Author(s):

Osmundo Dantas Pessoa-Neto ◽

Tiago Almeida Silva ◽

Vagner Bezerra dos Santos ◽

Orlando Fatibello-Filho

Keyword(s):

Light Emitting Diode ◽

Flow Analysis ◽

Photometric Determination ◽

Microfluidic System ◽

Experimental Conditions ◽

Light Emitting ◽

Experimental Parameters ◽

Led Photometer

A compact environmentally friendly microcontrolled microfluidic device ideal for in situ phosphate determination was developed based on a microsystem based on low-temperature co-fired ceramics (LTCC) coupled to a light-emitting diode (LED)–photometer with a multicommutation flow analysis (MCFA) approach. The experimental parameters of the MCFA analyzer were optimized by chemometric studies. Under the best experimental conditions, limits of detection and quantification of 0.02 mg P L–1 and 0.07 mg P L–1, respectively, and a sampling frequency of 67 h–1 were estimated. Moreover, a low sample consumption of only 60 μL per determination was the other advantage that fully meets the requirements of sustainable research and green chemistry purposes.

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Dimension control of in situ fabricated CsPbClBr2 nanocrystal films toward efficient blue light-emitting diodes

Nature Communications ◽

10.1038/s41467-020-20163-7 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Chenhui Wang ◽

Dengbao Han ◽

Junhui Wang ◽

Yingguo Yang ◽

Xinyue Liu ◽

...

Keyword(s):

Quantum Well ◽

Light Emitting Diodes ◽

Blue Emission ◽

Light Emitting ◽

Mixed Ligands ◽

Dimension Control ◽

Nanocrystal Films ◽

Width Distribution ◽

Quantum Well Width

AbstractIn the field of perovskite light-emitting diodes (PeLEDs), the performance of blue emissive electroluminescence devices lags behind the other counterparts due to the lack of fabrication methodology. Herein, we demonstrate the in situ fabrication of CsPbClBr2 nanocrystal films by using mixed ligands of 2-phenylethanamine bromide (PEABr) and 3,3-diphenylpropylamine bromide (DPPABr). PEABr dominates the formation of quasi-two-dimensional perovskites with small-n domains, while DPPABr induces the formation of large-n domains. Strong blue emission at 470 nm with a photoluminescence quantum yield up to 60% was obtained by mixing the two ligands due to the formation of a narrower quantum-well width distribution. Based on such films, efficient blue PeLEDs with a maximum external quantum efficiency of 8.8% were achieved at 473 nm. Furthermore, we illustrate that the use of dual-ligand with respective tendency of forming small-n and large-n domains is a versatile strategy to achieve narrow quantum-well width distribution for photoluminescence enhancement.

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An in situ sheet resistance study of oxidative-treated indium tin oxide substrates for organic light emitting display applications

Thin Solid Films ◽

10.1016/s0040-6090(02)00598-9 ◽

2002 ◽

Vol 417 (1-2) ◽

pp. 116-119 ◽

Cited By ~ 14

Author(s):

B.L. Low ◽

F.R. Zhu ◽

K.R. Zhang ◽

S.J. Chua

Keyword(s):

Sheet Resistance ◽

Tin Oxide ◽

Indium Tin Oxide ◽

Light Emitting ◽

Organic Light ◽

Oxide Substrates

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Excitonic Creation of Highly Luminescent Defects In Situ in Working Organic Light-Emitting Diodes

Advanced Optical Materials ◽

10.1002/adom.201700856 ◽

2017 ◽

Vol 6 (2) ◽

pp. 1700856 ◽

Cited By ~ 3

Author(s):

Yong-Biao Zhao ◽

Grayson L. Ingram ◽

Xi-Wen Gong ◽

Xi-Yan Li ◽

Li-Na Quan ◽

...

Keyword(s):

Light Emitting Diodes ◽

Organic Light Emitting Diodes ◽

Light Emitting ◽

Organic Light

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Suppressing the Initial Growth of Sidewall GaN by Modifying Micron-Sized Patterned Sapphire Substrate with H3PO4-Based Etchant

Micromachines ◽

10.3390/mi9120622 ◽

2018 ◽

Vol 9 (12) ◽

pp. 622 ◽

Cited By ~ 3

Author(s):

Wen-Yang Hsu ◽

Yuan-Chi Lian ◽

Pei-Yu Wu ◽

Wei-Min Yong ◽

Jinn-Kong Sheu ◽

...

Keyword(s):

Sapphire Substrate ◽

Light Emitting Diodes ◽

Ex Situ ◽

Initial Growth ◽

Patterned Sapphire Substrate ◽

Light Emitting ◽

Sapphire Substrates ◽

Patterned Sapphire Substrates

Micron-sized patterned sapphire substrates (PSS) are used to improve the performance of GaN-based light-emitting diodes (LEDs). However, the growth of GaN is initiated not only from the bottom c-plane but also from the sidewall of the micron-sized patterns. Therefore, the coalescence of these GaN crystals creates irregular voids. In this study, two kinds of nucleation layers (NL)—ex-situ AlN NL and in-situ GaN NL—were used, and the growth of sidewall GaN was successfully suppressed in both systems by modifying the micron-sized PSS surface.

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In Situ Fabrication of Bendable Microscale Hexagonal Pyramids Array Vertical Light Emitting Diodes with Graphene as Stretchable Electrical Interconnects

ACS Photonics ◽

10.1021/ph500133w ◽

2014 ◽

Vol 1 (5) ◽

pp. 421-429 ◽

Cited By ~ 21

Author(s):

Liancheng Wang ◽

Jun Ma ◽

Zhiqiang Liu ◽

Xiaoyan Yi ◽

Hongwei Zhu ◽

...

Keyword(s):

Light Emitting Diodes ◽

Light Emitting ◽

In Situ Fabrication ◽

Electrical Interconnects

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Low Driving Voltage of Organic Light-Emitting Diodes Using p-Doping Starburst Amine as Hole Transporter

MRS Proceedings ◽

10.1557/proc-660-jj5.23 ◽

2000 ◽

Vol 660 ◽

Author(s):

Xiang Zhou ◽

Andreas Nollau ◽

Jan Blochwitz ◽

Martin Pfeiffer ◽

Torsten Fritz ◽

...

Keyword(s):

Thin Films ◽

Hole Concentration ◽

Organic Light Emitting Diodes ◽

Driving Voltage ◽

Temperature Dependent ◽

Light Emitting ◽

Layer Sequence ◽

Undoped Material ◽

High Bulk

ABSTRACTWe investigate the electrical properties and the OLED application of controlledly doped amorphous hole transporters. Thin films of starburst amine, 4,4',4“-tris(N,N-diphenyl- amino) triphenylamine (TDATA), doped by a fully fluorinated form of tetracyano- quinodimethane (F4-TCNQ), are characterized in situ by temperature dependent conductivity and Seebeck measurements. The conductivity and hole concentration increase with dopant concentration and are many orders of magnitude higher than those of undoped material. OLED devices with the layer sequence ITO/TDATA(200 nm)/Alq3(65 nm)/LiF(1 nm)/Al were fabricated. The use of p-doped TDATA thin films with high bulk conductivity and hole concentration reduces the resistance of the devices and leads to a thinner space charge layer which facilitates injection of holes from the ITO anode.

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Fuzzy Based Network Assignment and Link-Switching Analysis in Hybrid OCC/LiFi System

Wireless Communications and Mobile Computing ◽

10.1155/2018/2870518 ◽

2018 ◽

Vol 2018 ◽

pp. 1-15 ◽

Cited By ~ 9

Author(s):

Moh. Khalid Hasan ◽

Mostafa Zaman Chowdhury ◽

Md. Shahjalal ◽

Yeong Min Jang

Keyword(s):

Hybrid System ◽

Communication Systems ◽

High Speed ◽

Light Emitting Diode ◽

Flow Analysis ◽

Optical Wireless Communications ◽

Light Emitting ◽

High Speed Data ◽

Transmission Capability ◽

Time Division

In recent times, optical wireless communications (OWC) have become attractive research interest in mobile communication for its inexpensiveness and high-speed data transmission capability and it is already recognized as complementary to radio-frequency (RF) based technologies. Light fidelity (LiFi) and optical camera communication (OCC) are two promising OWC technologies that use a photo detector (PD) and a camera, respectively, to receive optical pulses. These communication systems can be implemented in all kinds of environments using existing light-emitting diode (LED) infrastructures to transmit data. However, both networking layers suffer from several limitations. An excellent solution to overcoming these limitations is the integration of OCC and LiFi. In this paper, we propose a hybrid OCC and LiFi architecture to improve the quality-of-service (QoS) of users. A network assignment mechanism is developed for the hybrid system. A dynamic link-switching technique for efficient handover management between networks is proposed afterward which includes switching provisioning based on user mobility and detailed network switching flow analysis. Fuzzy logic (FL) is used to develop the proposed mechanisms. A time-division multiple access (TDMA) based approach, called round-robin scheduling (RRS), is also adopted to ensure fairness in time resource allocation while serving multiple users using the same LED in the hybrid system. Furthermore, simulation results are presented taking different practical application scenarios into consideration. The performance analysis of the network assignment mechanism, which is provided at the end of the paper, demonstrates the importance and feasibility of the proposed scheme.

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