The effect of inorganic/organic dual dielectric layers on the morphology and performance of n-channel OFETs

2016 ◽  
Vol 18 (17) ◽  
pp. 12163-12168 ◽  
Author(s):  
Anamika Kalita ◽  
Anamika Dey ◽  
Parameswar Krishnan Iyer

Excellent n-channel behavior was observed for cyclohexyl substituted naphthalene diimide with the highest μe value of 0.08 cm2 V−1 s−1, VTH as low as 0.5 V and ION/IOFF ratio of 104 under vacuum with a Al2O3/PVA dual dielectric layer.

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.


2009 ◽  
Vol 1156 ◽  
Author(s):  
Kazuyuki Kohama ◽  
Kazuhiro Ito ◽  
Kenichi Mori ◽  
Kazuyoshi Maekawa ◽  
Yasuharu Shirai ◽  
...  

AbstractA new fabrication technique to prepare ultra-thin barrier layers for nano-scale Cu wires was proposed in our previous studies. Ti-rich layers formed at the Cu(Ti)/dielectric-layer interfaces consisted of crystalline TiC or TiSi and amorphous Ti oxides. The primary control factor for Ti-rich interface layer composition was the C concentration in the dielectric layers rather than the formation enthalpy of the Ti compounds. To investigate Ti-rich interface layer growth in Cu(Ti)/dielectric-layer samples annealed in ultra high vacuum, Rutherford Backscattering Spectrometry (RBS) was employed in the present study. Ti peaks were obtained only at the interface for all the samples. Molar amounts of Ti atoms segregated to the interface (n) were estimated from Ti peak areas. The n value was defined by n = Z·exp(-E/RT) · tm, where Z is a preexponential factor and E the activation energy for the reaction. The Z, E, and m values were estimated from plots of log n vs log t and log n vs 1/T. The m values are similar in all the samples. The E values for Ti atoms reacting with the dielectric layers containing carbon (except SiO2) tended to decrease with decreasing C concentration (decreasing k), while reaction rate coefficients (Z·exp(-E/RT)) were insensitive to C concentration in the dielectric layers. These factors lead to conclusion that growth of the Ti-rich interface layers is controlled by chemical reactions of the Ti atoms with the dielectric layers represented by the Z and E values, rather than diffusion in the Ti-rich interface layers.


2013 ◽  
Vol 401-403 ◽  
pp. 929-932
Author(s):  
Ji Jiang Wu ◽  
Jin Xia Gao

The position-dependent extraordinary optical properties in near-zero-permittivity range for a one-dimensional superconducting photonic crystal consisting of alternating superconductor and dielectric layers are theoretically investigated by using the transfer matrix method. Based on the calculated reflectance spectrum, it is shown the extraordinary optical propriety depends on the relative position between the threshold wavelength and the photonic band gap. By suitably choosing the thickness of the superconducting or dielectric layer, one can design a transmission narrowband filter or resonator to satisfy their needs without introducing any physical defect in a superconducting photonic crystal.


2019 ◽  
Vol 52 (5-6) ◽  
pp. 657-664
Author(s):  
Yanmin Zhou ◽  
Zhe Yan ◽  
Bin He ◽  
Zhipeng Wang ◽  
Yafei Wang

Electronic skin (e-skin) has shown great application prospects in many fields due to its multiple advantages. Previous studies have illustrated that the structure with a dielectric layer sandwiched between two electrodes had good pressure-sensing abilities, and microstructures in the dielectric layer could improve the sensitivity. In this paper, we proposed mechanical models of e-skin sensing unit with different microstructures (flat, trapezoidal, half-cylinder, and pyramids) in the dielectric layer. Then, we performed finite element method simulations and experiments to validate the model. Finally, we demonstrated its application as the pressure-sensing unit for human hands, showing its great potentials in sensors of artificial prosthesis or soft robots in the future.


Nanoscale ◽  
2021 ◽  
Author(s):  
Hyeon Woo Park ◽  
Seung Dam Hyun ◽  
In Soo Lee ◽  
Suk Hyun Lee ◽  
Yong Bin Lee ◽  
...  

Charge injection from the near-by-electrode can occur during ferroelectric switching in the ferroelectric-dielectric bilayer due to the high field applied to the adjacent dielectric layers. The aim of this study...


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3328
Author(s):  
Yong Wang ◽  
Zihui Zhang ◽  
Long Guo ◽  
Yuxuan Chen ◽  
Yahui Li ◽  
...  

In this work, AlGaN-based deep-ultraviolet (DUV) light-emitting diodes (LEDs) with AlGaN as the dielectric layers in p+-Al0.55Ga0.45N/AlGaN/n+-Al0.55Ga0.45N polarization tunnel junctions (PTJs) were modeled to promote carrier tunneling, suppress current crowding, avoid optical absorption, and further enhance the performance of LEDs. AlGaN with different Al contents in PTJs were optimized by APSYS software to investigate the effect of a polarization-induced electric field (Ep) on hole tunneling in the PTJ. The results indicated that Al0.7Ga0.3N as a dielectric layer can realize a higher hole concentration and a higher radiative recombination rate in Multiple Quantum Wells (MQWs) than Al0.4Ga0.6N as the dielectric layer. In addition, Al0.7Ga0.3N as the dielectric layer has relatively high resistance, which can increase lateral current spreading and enhance the uniformity of the top emitting light of LEDs. However, the relatively high resistance of Al0.7Ga0.3N as the dielectric layer resulted in an increase in the forward voltage, so much higher biased voltage was required to enhance the hole tunneling efficiency of PTJ. Through the adoption of PTJs with Al0.7Ga0.3N as the dielectric layers, enhanced internal quantum efficiency (IQE) and optical output power will be possible.


Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 282 ◽  
Author(s):  
Zhihao Liang ◽  
Shangxiong Zhou ◽  
Wei Cai ◽  
Xiao Fu ◽  
Honglong Ning ◽  
...  

In this paper, zirconium–aluminum–oxide (ZAO) dielectric layers were prepared by a solution method with intent to combine the high dielectric constant with a low leakage current density. As a result, dielectric layers with improved electrical properties as expected can be obtained by spin-coating the mixed precursor. The chemical and physical properties of the films were measured by thermogravimetric differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and a UV spectrometer. It is observed that the oxygen defects and the hydroxide in the films are reduced with the addition of high-bond-energy zirconia, while the films can remain large optical bond gaps thanks to the presence of alumina. The metal-insulator-metal (MIM) devices were fabricated, and it was seen that with a molar ratio of Zr:Al = 3:1 and an annealing temperature of 500 °C, the dielectric layer afforded the highest dielectric constant of 21.1, as well as a relatively low leakage current of 2.5 10−6 A/cm2@1MV/cm. Furthermore, the indium–gallium–zinc oxide thin-film transistors (IGZO-TFTs) with an optimal ZAO dielectric layer were prepared by the solution method and a mobility of 14.89 cm2/Vs, and a threshold voltage swing of 0.11 V/dec and a 6.1 106 on/off ratio were achieved at an annealing temperature of 500 °C.


2018 ◽  
Vol 14 (2) ◽  
pp. 134-140
Author(s):  
Darius Plonis ◽  
Andrius Katkevičius ◽  
Diana Belova-Plonienė

AbstractModels of open cylindrical multilayer gyroelectric-anisotropic-gyroelectric waveguides are presented in this paper. The influence of density of free carriers, temperature and the presence of the external dielectric layer on the wave phase characteristics of the models of n-GaAs waveguides has been evaluated. Differential Maxwell’s equations, coupled mode and partial area methods have been used to obtain complex dispersion equation of the models of gyroelectric-anisotropic-gyroelectric waveguides with or without the temperature sensitive external anisotropic dielectric layer. The analysis has shown that the phase characteristics are practically unchanged when the density of electrons is equal to N = (1017–5·1018) m−3, d/rs = 0, the changes of wave phase coefficients are obtained in the models of waveguides with the external anisotropic dielectric layer. The largest differences of wave phase coefficient are obtained when the density of electrons is N = 1021 m−3. The external dielectric layer improves the control of gyroelectric n-GaAs waveguides with temperature.


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