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Balambiga B, Devibala P, Imran PM, Bhuvanesh NSP, Nagarajan S. High mobility and ON/OFF ratio of solution-processable p-channel OFETs from arylacetylene end-capped alkoxyphenanthrenes. Chemphyschem 2022; 23:e202200350. [PMID: 35867609 DOI: 10.1002/cphc.202200350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/30/2022] [Indexed: 11/10/2022]
Abstract
New arylacetylene end-capped alkoxyphenanthrenes were synthesized and demonstrated as the best active layer for solution-processable p -channel organic field-effect transistors. The alkoxy chain embedded compounds exhibited enhanced solubility and induced non-covalent interactions resulting in effective molecular packing. The 'Lewis soft' heteroatoms direct the most stable conformation with dihedral angles possible for molecular interactions, and energy levels. DFT studies supported the finetuning of FMOs, with high HOMO levels ~-5.2 eV ensuring a low barrier for charge injection. OFET devices exhibited a maximum charge carrier mobility up to 1.30 cm 2 /Vs with the highest ON/OFF ratio of 10 7 . The strong π-π interactions and the crystallinity of the films are well supported by GIXRD and SEM analysis.
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Affiliation(s)
| | | | | | - Natamai S P Bhuvanesh
- Texas A&M University College Station: Texas A&M University, Chemistry, UNITED STATES
| | - Samuthira Nagarajan
- Central University of Tamil Nadu, Chemistry, Neelakudi, 610101, Thiruvarur, INDIA
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2
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Wang S, Wang Z, Huang Y, Hu Y, Yuan L, Guo S, Zheng L, Chen M, Yang C, Zheng Y, Qi J, Yu L, Li H, Wang W, Ji D, Chen X, Li J, Li L, Hu W. Directly Patterning Conductive Polymer Electrodes on Organic Semiconductor via In Situ Polymerization in Microchannels for High-Performance Organic Transistors. ACS APPLIED MATERIALS & INTERFACES 2021; 13:17852-17860. [PMID: 33825449 DOI: 10.1021/acsami.1c01386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Conductive polymers are considered promising electrode materials for organic transistors, but the reported devices with conductive polymer electrodes generally suffer from considerable contact resistance. Currently, it is still highly challenging to pattern conductive polymer electrodes on organic semiconductor surfaces with good structure and interface quality. Herein, we develop an in situ polymerization strategy to directly pattern the top-contacted polypyrrole (PPy) electrodes on hydrophobic surfaces of organic semiconductors by microchannel templates, which is also applicable on diverse hydrophobic and hydrophilic surfaces. Remarkably, a width-normalized contact resistance as low as 1.01 kΩ·cm is achieved in the PPy-contacted transistors. Both p-type and n-type organic field-effect transistors (OFETs) exhibit ideal electrical characteristics, including almost hysteresis-free, low threshold voltage, and good stability under long-term test. The facile patterning method and high device performance indicate that the in situ polymerization strategy in confined microchannels has application prospects in all-organic, transparent, and flexible electronics.
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Affiliation(s)
- Shuguang Wang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Zhongwu Wang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Yinan Huang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Yongxu Hu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Liqian Yuan
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Shujing Guo
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Lei Zheng
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, 300072 Tianjin, China
| | - Mingxi Chen
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, 300072 Tianjin, China
| | - Chenhuai Yang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, 300072 Tianjin, China
| | - Yingshuang Zheng
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Jiannan Qi
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Li Yu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Hongwei Li
- Institute of Microscale Optoelectronics, Collaborative Innovation Centre for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen Key Laboratory of Micro-Nano Photonic Information Technology, Guangdong Laboratory of Artificial Intelligence and Digital Economy (SZ), Shenzhen University, 518060 Shenzhen, China
| | - Wenchong Wang
- Physikalisches Institut and Center for Nanotechnology (CeNTech), Universität Münster, 48149 Münster, Germany
| | - Deyang Ji
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Xiaosong Chen
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Jie Li
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
| | - Liqiang Li
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, 350207 Fuzhou, China
| | - Wenping Hu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, 300072 Tianjin, China
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, 300072 Tianjin, China
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, 350207 Fuzhou, China
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Lee H, Moon B, Son SY, Park T, Kang B, Cho K. Charge Trapping in a Low-Crystalline High-Mobility Conjugated Polymer and Its Effects on the Operational Stability of Organic Field-Effect Transistors. ACS APPLIED MATERIALS & INTERFACES 2021; 13:16722-16731. [PMID: 33543611 DOI: 10.1021/acsami.0c20965] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The effects of the microstructure of conjugated polymer thin films on charge trapping and operational stability of organic field-effect transistors (OFETs) are investigated. Device characteristics of OFETs based on two model conjugated polymers, poly(3-hexylthiophene) (P3HT) and a random 3-hexylthiophene-thiophene copolymer (RP33), are compared. P3HT films have high crystallinity and long-range molecular order, whereas RP33 films have low crystallinity and short-range molecular order as well as enhanced polymer backbone planarity. Experimental evidence shows that although the microstructure of the RP33 film provides efficient charge transport pathways, its high degree of structural disorder causes severe shallow trapping of charge carriers, which results in its inferior stability under bias stress. This study demonstrates that low-crystalline conjugated polymers with short-range order can provide a high charge-carrier mobility but at the same time be inappropriate for practical OFETs because of their poor intrinsic operational stability.
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Affiliation(s)
- Hansol Lee
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Byungho Moon
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Sung Yun Son
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Taiho Park
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Boseok Kang
- SKKU Advanced Institute of Nanotechnology (SAINT) and Department of Nano Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Kilwon Cho
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
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Abstract
Partial substitution of CH groups in the skeletons of linearly fused phenyl rings
provides an appreciable possibility to tailor their properties. Among them, azaacenes induced
from a partial substitution of oligoacenes by nitrogen are one of the most promising
derivatives with a view of their potential application in organic electronic devices as a
novel organic n-type semiconductor. Hence this review focuses on recent progress in the
synthesis of azaacenes and their applications beyond organic field-effect transistors
(OFETs) such as organic light-emitting diodes (OLEDs), phototransistors, photoelectrical
chemical cells, organic memory, solar cells, conductors and sensors.
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Affiliation(s)
- Yuechao Wu
- College of Chemical and Material Engineering, Quzhou University 324000, Quzhou, China
| | - Yi Jin
- College of Chemical and Material Engineering, Quzhou University 324000, Quzhou, China
| | - Jianguo Xu
- College of Chemical and Material Engineering, Quzhou University 324000, Quzhou, China
| | - Yanwen Lv
- College of Chemical and Material Engineering, Quzhou University 324000, Quzhou, China
| | - Jiangang Yu
- College of Chemical and Material Engineering, Quzhou University 324000, Quzhou, China
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Marszalek T, Gazicki-Lipman M, Ulanski J. Parylene C as a versatile dielectric material for organic field-effect transistors. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:1532-1545. [PMID: 28884059 PMCID: PMC5550802 DOI: 10.3762/bjnano.8.155] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 06/27/2017] [Indexed: 04/14/2023]
Abstract
An emerging new technology, organic electronics, is approaching the stage of large-scale industrial application. This is due to a remarkable progress in synthesis of a variety of organic semiconductors, allowing one to design and to fabricate, so far on a laboratory scale, different organic electronic devices of satisfactory performance. However, a complete technology requires upgrading of fabrication procedures of all elements of electronic devices and circuits, which not only comprise active layers, but also electrodes, dielectrics, insulators, substrates and protecting/encapsulating coatings. In this review, poly(chloro-para-xylylene) known as Parylene C, which appears to become a versatile supporting material especially suitable for applications in flexible organic electronics, is presented. A synthesis and basic properties of Parylene C are described, followed by several examples of use of parylenes as substrates, dielectrics, insulators, or protecting materials in the construction of organic field-effect transistors.
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Affiliation(s)
- Tomasz Marszalek
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120, Heidelberg, Germany
- InnovationLab, Speyererstr. 4, 69115 Heidelberg, Germany
- Department of Molecular Physics, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Maciej Gazicki-Lipman
- Institute for Materials Science and Engineering, Lodz University of Technology, Stefanowskiego 1-15, 90-924 Lodz, Poland
| | - Jacek Ulanski
- Department of Molecular Physics, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
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Khan MA, Chen H, Qu J, Trimby PW, Moody S, Yao Y, Ringer SP, Zheng R. Insights into the Silver Reflection Layer of a Vertical LED for Light Emission Optimization. ACS APPLIED MATERIALS & INTERFACES 2017; 9:24259-24272. [PMID: 28653527 DOI: 10.1021/acsami.7b04854] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this work, Ag as a highly reflective mirror layer of gallium nitride (GaN)-based blue vertical light-emitting diodes (VLEDs) has been systematically investigated by correlating scanning electron microscopy/energy dispersive X-ray spectroscopy/transmission Kikuchi diffraction/electron backscatter diffraction, aberration-corrected scanning transmission electron microscopy, and atomic force microscopy techniques. In the context of high-efficiency lighting, three critical aspects have been scrutinized on the nanoscale: (1) chemical diffusion, (2) grain morphology, and (3) surface topography of the Ag layer. We found that nanoscale inhomogeneous distribution of In in InGaN/GaN quantum wells (QWs), interfacial diffusion (In/Ga out-diffusion into the Ag layer and diffusion of Ag into p-GaN and QWs), and Ag agglomeration deteriorate the light reflectivity, which account for the decreased luminous efficiency in VLEDs. Meanwhile, the surface morphology and topographical analyses revealed the nanomorphology of the Ag layer, where a nanograin size of ∼300 nm with special nanotwinned boundaries and an extremely smooth surface of ∼3-4 nm are strongly desired for better reflectivity. Further, on the basis of these microscopy results, suggestions on light extraction optimization are given to improve the performance of GaN-based blue VLEDs. Our findings enable fresh and deep understanding of performance-microstructure correlation of LEDs on the nanoscale, providing guidance to the design and manufacture of high-performance LED devices.
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Affiliation(s)
| | | | | | | | | | - Yin Yao
- Electron Microscope Unit, University of New South Wales , Sydney, New South Wales 2052, Australia
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Padma N, Maheshwari P, Bhattacharya D, Tokas RB, Sen S, Honda Y, Basu S, Pujari PK, Rao TVC. Investigations on Substrate Temperature-Induced Growth Modes of Organic Semiconductors at Dielectric/semiconductor Interface and Their Correlation with Threshold Voltage Stability in Organic Field-Effect Transistors. ACS APPLIED MATERIALS & INTERFACES 2016; 8:3376-85. [PMID: 26761590 DOI: 10.1021/acsami.5b11349] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Influence of substrate temperature on growth modes of copper phthalocyanine (CuPc) thin films at the dielectric/semiconductor interface in organic field effect transistors (OFETs) is investigated. Atomic force microscopy (AFM) imaging at the interface reveals a change from 'layer+island' to "island" growth mode with increasing substrate temperatures, further confirmed by probing the buried interfaces using X-ray reflectivity (XRR) and positron annihilation spectroscopic (PAS) techniques. PAS depth profiling provides insight into the details of molecular ordering while positron lifetime measurements reveal the difference in packing modes of CuPc molecules at the interface. XRR measurements show systematic increase in interface width and electron density correlating well with the change from layer + island to coalesced huge 3D islands at higher substrate temperatures. Study demonstrates the usefulness of XRR and PAS techniques to study growth modes at buried interfaces and reveals the influence of growth modes of semiconductor at the interface on hole and electron trap concentrations individually, thereby affecting hysteresis and threshold voltage stability. Minimum hole trapping is correlated to near layer by layer formation close to the interface at 100 °C and maximum to the island formation with large voids between the grains at 225 °C.
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Affiliation(s)
| | | | | | | | | | - Yoshihide Honda
- The Institute of Scientific and Industrial Research, Osaka University , Ibaraki, Osaka, Japan
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