Tailoring the Dielectric Layer Structure for Enhanced Carrier Mobility in Organic Transistors: The Use of Hybrid Inorganic/Organic Multilayer Dielectrics

2016 ◽  
Vol 2 (5) ◽  
pp. 1500402 ◽  
Author(s):  
Muriel de Pauli ◽  
Ute Zschieschang ◽  
Ingrid D. Barcelos ◽  
Hagen Klauk ◽  
Angelo Malachias
2019 ◽  
Vol 7 (1) ◽  
pp. 1901824 ◽  
Author(s):  
Hyun Ho Choi ◽  
Hee Taek Yi ◽  
Junto Tsurumi ◽  
Jae Joon Kim ◽  
Alejandro L. Briseno ◽  
...  

2006 ◽  
Author(s):  
Toshihide Kamata ◽  
Sei Uemura ◽  
Manabu Yoshida ◽  
Kouji Suemori ◽  
Satoshi Hoshino ◽  
...  

2016 ◽  
Vol 7 (11) ◽  
pp. 2143-2150 ◽  
Author(s):  
Yao Li ◽  
He Wang ◽  
Xuesong Wang ◽  
Zuosen Shi ◽  
Donghang Yan ◽  
...  

A series of novel polymers as functional dielectric layers for pentacene thin-film transistors was synthesized and investigated to explore the relationship between the grain size and the charge carrier mobility with a single variable.


Nanoscale ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 5231-5239 ◽  
Author(s):  
Fengtian Xia ◽  
Xiao Wei Sun ◽  
Shuming Chen

Highly bright alternating-current (AC) driven quantum-dot light-emitting diodes (QLEDs) are demonstrated based on a single dielectric layer structure.


2019 ◽  
Author(s):  
◽  
Amrit Prasad Laudari

In this research we study the role of ferroelectric dielectrics in organic field-effect transistors (FETs) to understand the mechanism of charge transport in organic semiconductors. The ferroelectric nature of the polymer, poly(vinylidene fluoride) (PVDF)), has been known for over 45 years. However, its role in interfacial transport in organic/polymeric FETs is not that well understood. PVDF and its copolymer, polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE), as a dielectric in organic FETs is a perfect test-bed for conducting transport studies where a systematic tuning of the dielectric constant with temperature may be achieved. By choosing small molecule organic semiconductors -- pentacene and 6,13 bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) -- along with a copolymer PVDF-TrFE as the dielectric layer, the FET characteristics are monitored as a function of temperature. Pentacene FETs show a weak temperature dependence of the charge carrier mobility in the ferroelectric phase of PVDF-TrFE, which is attributed to polarization fluctuation driven transport resulting from a coupling of the charge carriers to the surface phonons of the dielectric layer. A negative coefficient of carrier mobility is observed in TIPS-pentacene upwards of 200 K with the ferroelectric dielectric, while an activated transport is observed with non-ferroelectric dielectrics. We show that this behavior is correlated with the nature of the trap states in TIPS-pentacene. We also developed the method of dipole engineering of the PVDF-TrFE films to enhance the properties of organic FETs. PVDF-TrFE, despite its applications in a vast range of work (including as a gate dielectric in organic FET and sensing applications) poses concerns such as higher conductivity compared to other polymer non-ferroelectric dielectrics. We have come up with new methods of electrical poling the dielectric layer to enhance FET performance as well as reduce gate leakage issues. We demonstrate the effect of polarization rotation in PVDF-TrFE on the performance of small-molecule-based organic FETs. The subthreshold swing and other transistor parameters in organic FETs can be controlled in a reversible fashion by switching the polarization direction in the PVDF-TrFE layer. We further demonstrate a novel method of selective poling of the dielectric layer. By using solution processed TIPS-pentacene as the organic semiconductor, it is shown that textured poling of the PVDF-TrFE layer dramatically improves FET properties compared to unpoled or uniformly poled ferroelectric films. The texturing is achieved by first vertically poling the PVDF-TrFE film and then laterally poling the dielectric layer close to the gate electrode. TIPS-pentacene FETs show on/off ratios of 105 and hole mobilities of 1 cm2/Vs under ambient conditions with operating voltages well below-4 V. This research opens prospects of achieving low-operating FETs without any expensive patterning techniques.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Han Wu ◽  
Shijun Ji ◽  
Ji Zhao ◽  
Chengxin Jiang ◽  
Handa Dai

A five-band metamaterial absorber (MMA) is presented. The proposed absorber consists of a three-layer structure of the top metal resonator, intermediate dielectric layer, and bottom metal plane. The top structure takes the centroid as the center and spreads out in a three-pronged shape with an average of 360°, and the ends bifurcate again. The calculation was carried out by the professional software to iteratively optimize the absorption effect of MMA in the microwave range. The results show that the MA has five peaks at resonant frequencies of 5.984 GHz, 12.232 GHz, 18.128 GHz, 18.414 GHz, and 20.592 GHz, with peaks of 0.9925, 0.9968, 0.9783, 0.9754, and 0.9975. By analyzing the electromagnetic field and surface current distribution of the absorber, the absorption mechanism is further verified, and the corresponding influence on the absorption spectrum is studied according to different polarization angles and incident angles. The effects of different resonator structure size and dielectric layer thickness on absorption rate were also discussed, and the distribution of electromagnetic fields is analyzed to reveal the existence of electric dipole resonance and magnetic resonance. Through comparing experiments and simulations, it is found that the peaks of the 1st, 2nd, and 5th have smaller absorption errors and frequency deviation, while the peaks of the 3rd and 4th have large ones. The five-band absorber has potential application in multiband electromagnetic stealth, bionic sensor, thermal radiation measuring instrument, and so on.


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