Room Temperature Sensing Achieved by GaAs Nanowires and oCVD Polymer Coating

Wang, Xiaoxue; Ermez, Sema; Göktaş, Hilal; Gradečak, Silvija; Gleason, Karen K.

doi:10.1002/marc.201700055

Cited by 5 publications

(4 citation statements)

References 33 publications

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“…38 This approach relies on the oxidative chemical vapour deposition (oCVD) 39,40 reaction of porphyrins with free meso and b positions using a suitable volatile oxidant (preferentially FeCl 3 ) for dehydrogenative coupling. The oCVD technique is been mainly used for the synthesis of poly(3,4ethylenedioxythiophene) (PEDOT) [41][42][43] and polyaniline (PANI) 44 nding application in organic electronics, 45 volatile compound detectors [46][47][48] and supercapacitors. 49,50 Furthermore, the oxidant acts as doping agent directly yielding conductive thin lms on virtually any substrates including sensitive substrates such as paper and polymers.…”

Section: Introductionmentioning

confidence: 99%

Molecular flattening effect to enhance the conductivity of fused porphyrin tape thin films

et al. 2020

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Section: Introductionmentioning

confidence: 99%

Molecular flattening effect to enhance the conductivity of fused porphyrin tape thin films

et al. 2020

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“…PS coating has demonstrated to improve the selectivity for n ‐pentane over methanol and toluene by 2.7‐ and 4.4‐fold, respectively, and such as device exhibited the high signal quality of ≈30 dB and short response time of ≈400 s . Wang et al demonstrated the similar hybrid sensing device using GaAs nanowires arrays instead of VA‐CNT which exhibited good sensitivity toward many organic vapor analytes. The hybrid sensing device based on oCVD CPs combines the merits of both kinds of sensors and has the advantages such as: nonpolar molecule detection at room temperature, high signal quality, good reversibility, and short response time, and retaining high surface area morphology of VA‐CNTs by the oCVD dry method.…”

Section: Devices On Nanostructured Surfacesmentioning

confidence: 99%

Device Fabrication Based on Oxidative Chemical Vapor Deposition (oCVD) Synthesis of Conducting Polymers and Related Conjugated Organic Materials

Gharahcheshmeh

Gleason

2018

Adv Materials Inter

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lightweight, wearable, and stretchable properties of CPs relative to traditional materials highlight the areas where CPs may find their niche in modern devices. [2] The fabrication of uniform CPs in large scale with high throughput roll-to-roll process is of great importance in industrial sectors. To achieve this purpose, chemical vapor deposition (CVD) along with other vapor deposition methods are the promising approaches to expedite the commercialization process of CPs in large-scale applications.For polymers which dissolve, films can be formed by solution-based methods such as dip-coating and spin-coating. However, CPs, particularly those formed from unfunctionalized monomers, are often insoluble or require solvents which are unsafe and costly to use. The lack of solubility is typically associated with a rigid backbone structure that promotes crystallite formation. As a result, dissolution requires overcoming the associated enthalpy of crystallization.The need for solubilizing polymers is eliminated by employing CVD as the thin film formation technique. A variety of different CVD processes have been developed for vapor phase reactants to undergo similar polymerization mechanisms as those reported for solution synthesis. [3] These include CVD polymer methods for chain growth by free radical or cationic initiation, or by condensation polymerization. For most conjugated macromolecules, the desired variant of the CVD method needs to mimic the step-growth polymerization mechanism in order to obtain optimized properties, such as electrical conductivity. This motivated the invention of oxidative CVD (oCVD) in which the vacuum chamber design, strategy for reactant vapor introduction, and process conditions are optimized for step-growth polymerization. Vapor deposition methods which are not mechanistically motivated, such as thermal evaporation, pulsed laser deposition, and plasma-enhanced CVD, can result in conjugated polymer films having properties that are insufficient for integration into many types of devices. Thus, one major significance of achieving conjugated polymers having highly desirable characteristics by oCVD is the ability to fabricate state-of-the-art optoelectronic and energy storage devices.The oCVD process is a single-step method to convert vapor phase monomers, along with vapors of oxidant, into thin CP films. [3,4] At the surface of the substrate, step-growth Conducting polymers (CPs) combine electronic conductivity, optical transparency, and mechanical flexibility compatible with lightweight substrates. Due to these features CPs exhibit promising performance for a wide range of applications including electronic, optoelectronic, electrochemical, optochemical, and energy storage and harvesting devices. Fabrication of high-quality CPs thin film in a large scale is of high demand in multiple industrial sectors. Chemical vapor deposition (CVD) is a promising approach for scale-up and commercialization of CPs in large-scale thin film applications by a roll-to-roll process. The CVD technique is a versati...

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“…The conjugated polymer is then synthesized through gas phase injection of 3,4-ethylenedioxythiophene (EDOT) as monomer and one oxidant. Further, the solid oxidant iron trichloride (FeCl 3 ) was the first and most common one to be studied, ,,− ,− although in recent years, liquid oxidants, namely, 3-thiophene acetic acid (TAA), vanadium oxytrichloride (VOCl 3 ), − sulfuric acide (H 2 SO 4 ), bromine (Br 2 ), molybdenum(V) chloride (MoCl 5 ), copper(II) chloride (CuCl 2 ), and antimony pentachloride (SbCl 5 ), ,− have replaced it with the aim of optimizing the performance of PEDOT and avoiding sublimation drawbacks. Among these candidates, SbCl 5 has recently emerged as one of the most commonly used precursors due to its low toxicity, high volatility, and cost-effectiveness compared to other compounds such as molybdenum(V) chloride (MoCl 5 ) or vanadium oxytrichloride (VOCl 3 ) .…”

Section: Introductionmentioning

confidence: 99%

Single-Step PEDOT Deposition by oCVD for ITO-Free Deep Blue OLEDs

Sekkat,

El Housseiny,

Poupaki

et al. 2023

ACS Appl. Polym. Mater.

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Organic light-emitting diodes (OLEDs) are emerging technologies for potential lighting and display applications. Transparent conductive electrodes (TCEs) play a crucial role in enabling the functionality and increased performance of these particular devices. Despite their widespread use, indium tin oxide (ITO) thin films have several significant drawbacks, including material scarcity, high costs associated with both materials and fabrication processes, and limited flexibility. To address these issues, we thoroughly investigate the deposition of poly(3,4-ethylenedioxythiophene) (PEDOT) thin films as a promising alternative to ITO using a single-step and dry method named oxidative chemical vapor deposition (oCVD). The impact of increasing the substrate temperature from 110 to 190 °C on the film’s structure and properties was revealed with an increase in the film conductivity to over 1600 S/cm at 170 °C and a total transmittance of 97% in the visible range. This increase was attributed to a change in the molecular structure of the conjugated polymer from benzoid to quinoid as revealed by Raman and FTIR measurements. The XPS results demonstrated an increase in the doping ratio with Cl-containing species and a reduction of impurities. GIXRD, HR-TEM, and AFM measurements indicated a smooth surface and a highly face-on orientation for all temperatures. The optimized TCE layers were successfully integrated into deep blue OLED devices emitting at 436 nm with stable color Commission Internationale de l’Energie (CIE) coordinates of (0.15, 0.08) under variation of the applied current. A satisfactory performance (72.1 cd/m2 and 0.86 W/sr·m2 at 10 mA cm–2) and an external quantum efficiency (EQE) of 1.04% were achieved. These results are quite promising, as OLEDs based on PEDOT as a TCE have demonstrated slightly better output performance in terms of luminance and radiance, with an increase in EQE by a factor of 1.7, compared to the reference device based on ITO.

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Room Temperature Sensing Achieved by GaAs Nanowires and oCVD Polymer Coating

Cited by 5 publications

References 33 publications

Molecular flattening effect to enhance the conductivity of fused porphyrin tape thin films

Molecular flattening effect to enhance the conductivity of fused porphyrin tape thin films

Device Fabrication Based on Oxidative Chemical Vapor Deposition (oCVD) Synthesis of Conducting Polymers and Related Conjugated Organic Materials

Single-Step PEDOT Deposition by oCVD for ITO-Free Deep Blue OLEDs

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