Enhanced Charge Injection Properties of Organic Field‐Effect Transistor by Molecular Implantation Doping

Organic semiconductors (OSCs) have been widely studied due to their merits such as mechanical flexibility, solution processability, and large‐area fabrication. However, OSC devices still have to overcome contact resistance issues for better performances. Because of the Schottky contact at the metal–OSC interfaces, a non‐ideal transfer curve feature often appears in the low‐drain voltage region. To improve the contact properties of OSCs, there have been several methods reported, including interface treatment by self‐assembled monolayers and introducing charge injection layers. Here, a selective contact doping of 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F₄‐TCNQ) by solid‐state diffusion in poly(2,5‐bis(3‐hexadecylthiophen‐2‐yl)thieno[3,2‐b]thiophene) (PBTTT) to enhance carrier injection in bottom‐gate PBTTT organic field‐effect transistors (OFETs) is demonstrated. Furthermore, the effect of post‐doping treatment on diffusion of F₄‐TCNQ molecules in order to improve the device stability is investigated. In addition, the application of the doping technique to the low‐voltage operation of PBTTT OFETs with high‐k gate dielectrics demonstrated a potential for designing scalable and low‐power organic devices by utilizing doping of conjugated polymers.     

Automatic recognition and suppression of holes on mold bases for finite element applications

Engineering with Computers - As the required accuracy of mold flow analysis has recently increased, it has become necessary to consider all components of a mold base and to generate solid meshes...     

Preparation and luminescent properties of CaF2:Ln3+ (Ln:Er,Er/Yb)/Nafion composite films

In this work, CaF_2:Ln~(3+)(Ln:Er,Er/Yb)/Nafion composite films were prepared using Nafion as modifications and matrices by dripping method. The composite films were characterized by Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD) and scanning electron microscopy(SEM). Composite films are transparent and CaF_2:Ln~(3+)(Ln:Er,Er/Yb) nanoparticles are well dispersed in Nafion films.The thicknesses of CaF_2:Er~(3+)/Nafion and CaF_2:Er~(3+),Yb~(3+)/Nafion composite film are about 77 and 73 μm,respectively. The nanoparticles in composite film possess cubic phase. CaF_2:Er~(3+),Yb~(3+)/Nafion composite film has stronger characteristic emission of Er~(3+) around 1530 nm with full width at half-maximum(FWHM) of 73 nm and longer luminescence lifetimes of 22.04 μs(25.03%) and 100.77 μs(74.97%).     

A web-based 3D ontology navigation system for spinal disease diagnosis

The Journal of Supercomputing - This paper presents a web-based three-dimensional (3D) navigation system for a spinal disease ontology using a 3D virtual human spine. The 3D navigation system...     

Parametric Solutions to the Generalized Discrete Yakubovich‐Transpose Matrix Equation

This paper is concerned with the complete parametric solutions to the generalized discrete Yakubovich‐transpose matrix equation X − AX^TB = CY. which is related with several types of matrix equations in control theory. One of the parametric solutions has a neat and elegant form in terms of the Krylov matrix, a block Hankel matrix and an observability matrix. In addition, the special case of the generalized discrete Yakubovich‐transpose matrix equation, which is called the Karm‐Yakubovich‐transpose matrix equation, is considered. The explicit solutions to the Karm‐Yakubovich‐transpose matrix equation are also presented by the so‐called generalized Leverrier algorithm. At the end of the paper, two examples are given to show the efficiency of the proposed algorithm.     

Catalytic Upgrading of Phenolic Oil by Etherification with Methanol

Catalytic etherification of phenolic oil with methanol was investigated to decrease the polarity and acidity of the product oil. The catalyst KH₂PO₄/activated alumina (AA) provided the best performance due to its excellent dehydration and anti‐coking property. When catalyzed by KH₂PO₄‐AA, the content of aryl ethers increased with rising temperature during the early stage but decreased at 500 °C. Alkoxy phenols had an inhibiting effect on etherification of alkyl phenols due to adsorption competition. Aryl ethers were mostly generated from alkyl phenols, while alkoxy phenols also contributed by simultaneous conversion to dialkoxybenzenes and diphenols, with a higher selectivity to diphenols. This explained the reduced alkoxy phenols and more generated alkyl phenols and aryl ethers at 350 °C.     

Comparison of cavern formation in massive salt blocks with single-well and two-well systems

The authors of this article have conducted a comparison study to investigate the construction characteristics of both single-well and two-well systems; two model experiments were conducted using large-size moulded rock salt specimens. An experimental platform was designed to simulate the process of leaching and a theoretical equation of calculating and predicting the cavern volume was derived. The experimental results illustrate that the variation trend of brine instantaneous concentration for single-well and two-well systems is identical, and an equilibrium state appears at last. Moreover, the equilibrium is reached early, after 5–8 pumping cycles. The construction rate in the two-well system is faster than the single-well system, and this phenomenon is observed mainly in the early periods (1–3 pumping cycles). Besides, the cavern shapes for the two construction methods are also found to be distinctive. The cavern of the single-well system has a circular cross section and an axisymmetric profile while that of the two-well system has an ovular cross section and a non-axisymmetric profile.