Oxidative MLD of Conductive PEDOT Thin Films with EDOT and ReCl<sub>5</sub> as Precursors

Ghafourisaleh, Saba; Popov, Georgi; Leskelä, Markku; Putkonen, Matti; Ritala, Mikko

doi:10.1021/acsomega.1c02029

Cited by 10 publications

(21 citation statements)

References 67 publications

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“…The self-terminating surface reactions in MLD processes allow for the formation of uniform coatings on complex 3D surfaces. ,, oMLD is similar to conventional MLD but employs alternating exposures of a monomer and gas-phase chemical oxidant to drive surface-based radical polymerization reactions. To date, pEDOT is the only polymer that has been demonstrated using the oMLD technique. ,, …”

Section: Introductionmentioning

confidence: 99%

Oxidative Molecular Layer Deposition of Amine-Containing Conjugated Polymer Thin Films

Wyatt

Vaninger

Paranamana

et al. 2022

ACS Appl. Polym. Mater.

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Conjugated polymers such as polyethylenedioxythiophene (pEDOT), polypyrrole (pPy), and polyaniline (pAni) exhibit high electrochemical capacities, making them appealing as electrode materials for energy storage, electrochemical desalination, and chemical sensing. Recent work has established the growth of thin films of pEDOT using alternating gas-phase exposures of the EDOT monomer and a metal chloride (e.g., MoCl 5 ) oxidant in a process termed oxidative molecular layer deposition (oMLD). Here, we describe the first demonstration of oMLD of amine-containing conjugated polymers. We find that pyrrole (Py) and MoCl 5 undergo self-limiting surface reactions during oMLD exposures to form conformal pPy thin films, but oMLD using aniline (Ani) and p-phenylenediamine (PDA) monomers yields unexpected azo functionality. The formation of azo groups is attributed to an MoCl 5 -amine surface adduct that spatially constrains polymerization reactions near the amine group and produces azo groups when coupling two primary amines. pPy grown by oMLD exhibits a record-breaking 282 mAh/g capacity in an aqueous electrolyte, and PDA/MoCl 5 oMLD yields azo polymers of interest as anode materials for alkali-ion batteries. Alternating between Py and PDA monomers during oMLD produces molecularly assembled copolymers with qualitatively different electrochemical responses from the isolated monomer structures. This work lays the foundation for the growth of conformal thin films of conjugated amine polymers with molecular-level control of composition and thickness.

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Section: Introductionmentioning

confidence: 99%

Oxidative Molecular Layer Deposition of Amine-Containing Conjugated Polymer Thin Films

Wyatt

Vaninger

Paranamana

et al. 2022

ACS Appl. Polym. Mater.

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“…22,23 Recently, deposition of PEDOT was realized with MLD through oxidization of EDOT monomers with oxidant precursors, including MoCl 5 and ReCl 5 . 24,25 Although the reaction mechanism still needs to be further understood, these reports demonstrate a feasibility to deposit high-quality OSC films by utilizing the advantages of the MLD technology.…”

Section: ■ Introductionmentioning

confidence: 93%

“…Atomic or molecular layer deposition (ALD/MLD) has been extensively applied in film growth due to its feasibility to grow highly conformal and uniform films with precisely controlled nanoscale thicknesses. − Particularly, MLD can be used to synthesize polymers through condensation polymerization between different multifunctional organic precursors, e.g., ultrathin polythiourea films were successfully deposited by MLD through the coupling reaction of isothiocyanates and amines. , However, most OSCs, including polythiophene, polypyrrole, and poly(3,4-ethylenedioxythiophene) (PEDOT), cannot be synthesized by condensation reactions, and thus are difficult to be deposited using the MLD method. , Recently, deposition of PEDOT was realized with MLD through oxidization of EDOT monomers with oxidant precursors, including MoCl 5 and ReCl 5 . , Although the reaction mechanism still needs to be further understood, these reports demonstrate a feasibility to deposit high-quality OSC films by utilizing the advantages of the MLD technology.…”

Section: Introductionmentioning

confidence: 99%

High-Performance Flexible Gas Sensors Based on Layer-by-Layer Assembled Polythiophene Thin Films

Tan

Liu

et al. 2021

Chem. Mater.

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Gas sensors using organic semiconductors (OSCs) as active materials possess many advantages, including tunable selectivity and intrinsic flexibility, but still suffer from slow response and limited sensitivity. Ultrathin OSC films with high surface-to-volume ratios can improve the sensing performance; however, fabrication of continuous and uniform ultrathin OSC films using conventional methods remains challenging. In this work, we introduce a layer-by-layer assembly method, which is derived from the concept of atomic/molecular layer deposition technology, to prepare polythiophene OSC films under precise control. The resulting polythiophene film exhibits a linear growth as a function of the deposition cycle, and the nanoscale ultrathin films present a good thickness uniformity and smooth surface, in contrast to the uneven porous structure of spin-coated films. The assembly mechanism is revealed based on the detailed characterization of the polythiophene films. Further, the fabricated gas sensor using the layer-by-layer assembled polythiophene film as an active layer exhibits a 17%/ppm sensitivity to ammonia and a response time of less than 2 s, which is much superior to its counterpart with the spin-coated polythiophene film and is the best performance compared to previous reports. Flexible gas sensors are further demonstrated by depositing the film on a polymer substrate using the abovementioned method. Therefore, this work provides a widely applicable method to precisely deposit ultrathin and uniform OSC films for advanced applications.

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“…New organic components have also been developed for the purely organic MLD processes; the MLD material library already includes, besides the initially introduced polyimides [ 15,17–22,137–143 ] and polyamides, [ 15,23–28,144–149 ] many other polymers: polyurea, [ 29,30,37,38,51,150–164 ] polythiourea, [ 52 ] polyurethane, [ 165,166 ] polyazomethine, [ 167–172 ] poly(3,4‐ethylenedioxy‐thiophene), [ 173–177 ] polyimide–polyamide, [ 141 ] poly(ethylene terephthalate) (PET), [ 50,178–180 ] and others. [ 31,32,39–44,176,181–200 ] In recent years, the organic precursor library has been rapidly expanding.…”

Section: Organic Precursors In Ald/mldmentioning

confidence: 99%

Atomic/Molecular Layer Deposition for Designer's Functional Metal–Organic Materials

Multia

Karppinen

2022

Adv Materials Inter

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organic ligands act as bridges between the metal centers to form infinite 1D, 2D, or 3D structures. These materials are often referred to as coordination polymer (CP) [1] or metal-organic framework (MOF) [2] materials; the latter term is used when the metal-organic material is crystalline and highly porous. [3] The research field of CP-and MOF-type materials has grown tremendously over the last two decades. The structural and chemical diversity of these materials has served as a continuous source of scientific excitement; the same diversity has also triggered huge technological interest as these materials possess enormous potential to be tailored for a wide variety of applications ranging from gas capture, storage, and separation to sensing, catalysis, optics, electronics, and energy storage. [4][5][6][7] Most of the targeted application breakthroughs of metal-organics require that these materials can be produced as highquality thin films and coatings, which can be integrated with the other components in the actual device configuration. The possibility to deposit such thin films in an industry-feasible manner on the substrate types needed, would be a major step forward in the field. [8] Traditionally, solvent-based processes such as liquid-phase epitaxy, Langmuir-Blodgett, layer-by-layer, and electrochemical deposition techniques have been used for metal-organic thin films. [9][10][11] These are, however, incompatible with the requirements set by the possible integration of the materials in microelectronics. This is due to corrosion and contamination risks, and the problems in patterning and precise deposition on high-aspect-ratio features. Hence, it is vital to develop solventfree thin-film deposition routes for the metal-organic material family. In the optimal case, these deposition methods should allow conformal coatings on large-area and high-aspect-ratio substrates.The currently strongly emerging ALD/MLD technique is uniquely suited to address the challenge in a scientifically elegant yet industrially feasible way. This technique is derived from the two parent gas-phase thin-film techniques: ALD for inorganic materials (mostly binary metal oxides, sulfides, and nitrides), [12][13][14] and its counterpart MLD for purely organic thin films (e.g., polyimides and polyamides). [15] In both cases, the attractive film growth characteristics are derived from the unique way of separating the different precursor gas pulses. Currently, ALD is the standard thin-film technology in many Atomic layer deposition (ALD) for high-quality conformal inorganic thin films is one of the cornerstones of modern microelectronics, while molecular layer deposition (MLD) is its less-exploited counterpart for purely organic thin films. Currently, the hybrid of these two techniques, i.e., ALD/MLD, is strongly emerging as a state-of-the-art gas-phase route for designer's metal-organic thin films, e.g., for the next-generation energy technologies. The ALD/MLD literature comprises nearly 300 original journal papers covering most of the alkali...

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Oxidative MLD of Conductive PEDOT Thin Films with EDOT and ReCl₅ as Precursors

Cited by 10 publications

References 67 publications

Oxidative Molecular Layer Deposition of Amine-Containing Conjugated Polymer Thin Films

Oxidative Molecular Layer Deposition of Amine-Containing Conjugated Polymer Thin Films

High-Performance Flexible Gas Sensors Based on Layer-by-Layer Assembled Polythiophene Thin Films

Atomic/Molecular Layer Deposition for Designer's Functional Metal–Organic Materials

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Oxidative MLD of Conductive PEDOT Thin Films with EDOT and ReCl5 as Precursors

Cited by 10 publications

References 67 publications

Oxidative Molecular Layer Deposition of Amine-Containing Conjugated Polymer Thin Films

Oxidative Molecular Layer Deposition of Amine-Containing Conjugated Polymer Thin Films

High-Performance Flexible Gas Sensors Based on Layer-by-Layer Assembled Polythiophene Thin Films

Atomic/Molecular Layer Deposition for Designer's Functional Metal–Organic Materials

Contact Info

Product

Resources

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Oxidative MLD of Conductive PEDOT Thin Films with EDOT and ReCl₅ as Precursors