scholarly journals Charge Transient and Electrochemical Measurements as a Tool for Characterization and Degradation Study of Organic Semiconductors - PMPSis and MEH-PPV

2011 ◽  
Author(s):  
V. Nadazdy ◽  
K. Gmucova ◽  
S. Lanyi ◽  
F. Schauer ◽  
I. Kuritka
Keyword(s):  
Organic Semiconductors ◽  
Electrochemical Measurements ◽  
Degradation Study

Perfluoroalkyl-annelated conjugated systems toward n-type organic semiconductors

2008 ◽  
Vol 80 (3) ◽  
pp. 589-597 ◽  
Author(s):  
Yutaka Ie ◽  
Yoshikazu Umemoto ◽  
Masashi Nitani ◽  
Yoshio Aso
Keyword(s):  
Organic Semiconductors ◽  
Electron Mobility ◽  
Field Effect ◽  
Energy Levels ◽  
Electrochemical Measurements ◽  
Lumo Energy ◽  
X Ray ◽  
Conjugated Systems ◽  
Semiconducting Behavior

The syntheses of perfluoroalkyl-annelated conjugated units: hexafluorocyclopenta[c]thiophene, 4,4-difluoro-4H-cyclopenta[2,1-b:3,4-b']dithiophene, and 6,6,12,12-tetrafluoroindeno[3,2-b]fluorine, and these-containing oligomers have been accomplished. The annelation of the perfluoroalkyl groups effectively lowers the lowest unoccupied molecular orbitral (LUMO) energy levels without disrupting the effective conjugation of the backbones, which was unambiguously clarified by spectroscopic and electrochemical measurements as well as X-ray analysis. The perfluoroalkyl-annelated oligothiophenes exhibited n-type semiconducting behavior with field-effect electron mobility up to 0.018 cm2 V-1 s-1.

Energetic Control of Redox-Active Polymers Towards Safe Organic Bioelectronic Materials

2019 ◽  
Author(s):  
Alexander Giovannitti ◽  
Reem B. Rashid ◽  
Quentin Thiburce ◽  
Bryan D. Paulsen ◽  
Camila Cendra ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Organic Semiconductors ◽  
Side Reaction ◽  
Semiconducting Polymers ◽  
Side Reactions ◽  
Redox Active ◽  
Donor Acceptor ◽  
Electrochemical Devices ◽  
Biological Environment ◽  
Device Operation

<p>Avoiding faradaic side reactions during the operation of electrochemical devices is important to enhance the device stability, to achieve low power consumption, and to prevent the formation of reactive side‑products. This is particularly important for bioelectronic devices which are designed to operate in biological systems. While redox‑active materials based on conducting and semiconducting polymers represent an exciting class of materials for bioelectronic devices, they are susceptible to electrochemical side‑reactions with molecular oxygen during device operation. We show that this electrochemical side reaction yields hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), a reactive side‑product, which may be harmful to the local biological environment and may also accelerate device degradation. We report a design strategy for the development of redox-active organic semiconductors based on donor-acceptor copolymers that prevent the formation of H<sub>2</sub>O<sub>2</sub> during device operation. This study elucidates the previously overlooked side-reactions between redox-active conjugated polymers and molecular oxygen in electrochemical devices for bioelectronics, which is critical for the operation of electrolyte‑gated devices in application-relevant environments.</p>

Quantitative Image Analysis of Fractal-like Thin Films of Organic Semiconductors

2018 ◽  
Author(s):  
Weikun Zhu ◽  
Erfan Mohammadi ◽  
Ying Diao
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Image Analysis ◽  
Fractal Dimension ◽  
Organic Semiconductors ◽  
Film Growth ◽  
Electronic Device ◽  
Significant Control ◽  
Semiconductor Thin Films ◽  
Two Parameters

Morphology modulation offers significant control over organic electronic device performance. However, morphology quantification has been rarely carried out via image analysis. In this work, we designed a MATLAB program to evaluate two key parameters describing morphology of small molecule semiconductor thin films: fractal dimension and film coverage. We then employ this program in a case study of meniscus-guided coating of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C<sub>8</sub>-BTBT) under various conditions to analyze a diverse and complex morphology set. The evolution of morphology in terms of fractal dimension and film coverage was studied as a function of coating speed. We discovered that combined fractal dimension and film coverage can quantitatively capture the key characteristics of C<sub>8</sub>-BTBT thin film morphology; change of these two parameters further inform morphology transition. Furthermore, fractal dimension could potentially shed light on thin film growth mechanisms.

Design and Synthesis of Two-Dimensional Covalent Organic Frameworks with Four-Arm Cores: Prediction of Remarkable Ambipolar Charge-Transport Properties

2019 ◽  
Author(s):  
Simil Thomas ◽  
Hong Li ◽  
Raghunath R. Dasari ◽  
Austin Evans ◽  
William Dichtel ◽  
...  
Keyword(s):  
Charge Transport ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Polymer Networks ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
Zinc Porphyrin ◽  
Design And Synthesis ◽  
Predicted Values

<p>We have considered three two-dimensional (2D) π-conjugated polymer networks (i.e., covalent organic frameworks, COFs) materials based on pyrene, porphyrin, and zinc-porphyrin cores connected <i>via</i> diacetylenic linkers. Their electronic structures, investigated at the density functional theory global-hybrid level, are indicative of valence and conduction bands that have large widths, ranging between 1 and 2 eV. Using a molecular approach to derive the electronic couplings between adjacent core units and the electron-vibration couplings, the three π-conjugated 2D COFs are predicted to have ambipolar charge-transport characteristics with electron and hole mobilities in the range of 65-95 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>. Such predicted values rank these 2D COFs among the highest-mobility organic semiconductors. In addition, we have synthesized the zinc-porphyrin based 2D COF and carried out structural characterization via powder X-ray diffraction and surface area analysis, which demonstrates the feasability of these electroactive networks.</p>

Efficient Electron Injection into Organic Semiconductors Induced by Hydrogen Bonds

2019 ◽  
pp. 840
Author(s):  
Hirohiko Fukagawa ◽  
Munehiro Hasegawa ◽  
Katsuyuki Morii ◽  
Kazuma Suzuki ◽  
Tsubasa Sasaki ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Organic Semiconductors ◽  
Electron Injection
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