Numerical Simulation for Enhancing Performance of MoS2 Hetero-Junction Solar Cell Employing Cu2O as Hole Transport Layer

The paper reported the design and thorough analysis of a thin-film solar cell (TFSC) based on molybdenum disulfide (MoS2) with an integrated Copper(I) Oxide (Cu2O) hole transport layer (HTL), employing the one-dimensional Solar Cell Capacitance Simulator (SCAPS-1D) software. By varying crucial parameters such as absorber layer thickness, doping density, and bulk defect density, as well as HTL thickness, doping concentration, and electron affinity, defect density at ZnO/absorber and absorber/Cu2O interfaces, and operating temperature, we explored key photovoltaic measures including open circuit voltage (Voc), short-circuit current density (Jsc), fill-factor (FF), and power conversion efficiency (PCE) of the hetero-junction solar cell. The study demonstrated an efficiency of 18.87% for the MoS2 solar cell without HTL, while the proposed solar cell (SC) utilizing Cu2O HTL and optimized device structure exhibited a remarkable PCE of 26.70%. The outcomes derived from the present study offer valuable insights for the progress of a highly efficient and economically viable MoS2 hetero-junction TFSC.

Ge/Si heterojunction L-shape tunnel field-effect transistors with hetero-gate-dielectric

A Ge/Si heterojunction L-shaped tunnel field-effect transistor combined with hetero-gate-dielectric （GHL-TFET） is proposed and investigated by TCAD simulation. Current-voltage characteristics, energy-band diagrams, and the distri- bution of the band-to-band tunneling （BTBT） generation rate of GHL-TFET are analyzed. In addition, the effect of the vertical channel width on the ON-current is studied and the thickness of the gate dielectric is optimized for better suppression of ambipolar current. Moreover, analog/RF figure-of-merits of GHL-TFET are also investigated in terms of the cut-off frequency and gain bandwidth production. Simulation results indicate that the ON-current of GHL-TFET is increased by about three orders of magnitude compared with that of the conventional L-shaped TFET. Besides, the introduction of the hetero-gate-dielectric not only suppresses the ambipolar current effectively but also improves the analog/RF performance drastically. It is demonstrated that the maximum cut-off frequency of GHL-TFET is about 160 GHz, which is 20 times higher than that of the conventional L-shaped TFET.

Hetero-VRS检测方法的建立及其临床意义

目的 初步建立异质性万古霉素耐药葡萄球菌(Hetero-VRS)的检测方法,并对其检测的临床意义进行探讨。方法 采用纸片法、万古霉素联合β-内酰胺抗生素快速筛选法和菌谱分析法同时进行Het-ero-VRSA检测。结果 共检测17个对万古霉素敏感性降低的亚克隆,其中只有一个亚克隆的MIC为32μg/ml,其它16个亚克隆的MIC为8-16μg/ml;葡萄球菌对万古霉素的耐药性表现出明显的异质性。结论 万古霉素联合β-内酰胺抗生素快速筛选法和菌谱分析法都是Hetero-VRSA检测的有效方法,后者检测Hetero-VRSA的灵敏度能够达到10-8;纸片法不是Hetero-VRS检测的理想方法;Hetero-VRS的出现,应该引起我国医学界的广泛关注。

Novel dihydropyrazole derivatives linked with multi(hetero)aromatic ring:Synthesis and antibacterial activity

Eight novel heterocycle-substituted dihydropyrazole derivatives were synthesized and characterized by ESI-MS, ^1H NMR and ^13C NMR. All of the compounds have been screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results show that compounds 9b, 9g and 9h displayed significant activity with MIC values in the range of 0.39-1.562 μlmL against B. subtilis.

Prevalence,histologic and clinical characteristics of heterotopic gastric mucosa in Chinese patients

AIM:To determine the prevalence,demographic,clinical and histopathologic features of heterotopic gastric mucosa(HGM)in Chinese patients.METHODS:Patients referred to three endoscopy units were enrolled in this study.The macroscopic characteristics of HGM were documented.Biopsies were obtained and observed using hematoxylin and eosin staining.Helicobacter pylori colonization was examinedby Whartin-Starry staining.RESULTS:HGM was observed in 420 Chinese patients,yielding a prevalence of 0.4%.The majority of patients had a single patch(300/420;71.4%),while the remainder had two(84/420;20%)or multiple patches(36/420;8.6%).The size of the patches and the distance from the patch to the frontal incisor teeth varied significantly.The large majority of HGM patches were flat(393/420;93.6%),whereas the remaining patches were slightly elevated.The primary histological characteristic was fundic-type(216/420;51.4%)within the HGM patch,and antral-(43/420;10.2%)and transitional-type(65/420;15.5%)mucosa were also observed.The prevalence of intestinal metaplasia was3.1%(13/420)and the prevalence of dysplasia was1.4%(6/420),indicating the necessity for endoscopic follow-up in patients with HGM.Esophageal and extraesophageal complaints were also observed in patients with HGM.Dysphagia and epigastric discomfort(odds ratios:6.836 and 115.826,respectively;P s<0.05)were independent risk factors for HGM.CONCLUSION:Clinical complaints should be considered to improve the detection rate of HMG.The prevalence of intestinal metaplasia and dysplasia also indicates a need for endoscopic follow-up.

Intelligent Network Selection for Data Offloading in 5G Multi-Radio Heterogeneous Networks

In next generation networks, multiradio networks are emerging in order to deal with exponential data traffic increasing. Integrated Femto-WiFi(IFW) small cells have been introduced by 3GPP to offload data from cellular networks recently. These IFW cells are multi-mode capable(i.e., both licensed bands via cellular interface and unlicensed bands via WiFi interface). Therefore how to offload data effectively has become one of the most significant discussions in 5G Multi-Radio Heterogeneous Network. So far, most researches mainly focus on the generality of UEs, few attention has been paid to UEs' individual requirements. Considering UE's preference vary from individual to individual, in this paper, we present an UE preference-aware network selection scheme for mobile data offloading. It intelligently supports the distribution of heterogeneous classes of services, considers different types of UEs and delay-tolerant flows, and handles the mobility of UEs. The simulation results show the superiority of the proposed algorithm in user fairness, enhanced capacity and energy saving maximization.

Ionothermal Synthesis, Crystal Structure and Antibacterial Activities of a New 3d-4f Hetero-metallic Compound Containing Two Kinds of Ligands

A new 3d-4f（CuⅡ-CeⅢ） hetero-metallic compound containing two kinds of ligands, namely [CuⅡ（H2pdc）（phen）（H2O）]（HⅢ3O）2[CeⅢ（pdc）3][CuⅡ（phen）Ce（pdc）3]（1, H2 pdc = pyridine-2,6-dicarboxylic acid, phen = 1,10-phenanthroline）, has been synthesized by an ionothermal method using the ionic liquid 3-butyl-1-methylimidazolium bromide（[Bmim]Br） as solvent, and characterized by elemental analysis, energy-dispersive X-ray spectroscopy（EDS）, IR, XPS and single-crystal X-ray diffraction. The structure reveals that 1 belongs to the triclinic system, space group P1 with a = 12.044（7）, b = 14.841（8）, c = 22.305（13） A, α = 85.802（12）, β = 85.471（12）, γ = 89.174（11）°, Z = 2, V = 3964（4） A3, Dc = 1.804 g·cm-3, F（000） = 2140, μ = 1.757 mm-1, the final R = 0.0734, wR = 0.1094 and S = 1.013. The compound can be viewed as a two-dimensional layered structure composed by 3d-4f hetero-nuclear anions [Cu（phen）Ce（pdc）3]-, coordination cations [Cu（H2pdc）（phen）（H2O）]2＋, coordination anions [Ce（pdc）3]3- and protonated water molecules via hydrogen bonding interactions and π-π stacking. Moreover, the antimicrobial activities of 1 have been also investigated. The results indicated that its inhibitory activity is slightly higher than that of penicillin against Candida albicans.

Computational Study on the Hetero-Diels-Alder Reactions between Phosphonodithioformate and Butadienes

The mechanism, catalytic effect and substituent effect of the hetero-Diels-Alder reactions between phosphonodithioformate and butadienes have been investigated theoretically using density functional theory at the B3LYP/6-31G（d） level. The results show that all of these reactions proceed in a concerted but asynchronous way. In some reactions the formation of C-S bond is prior to that of C-C and opposite result is found in other reactions. The BF3 catalyst and trimethylsilyloxy group may lower the activation barriers by changing the energies of FMOs for reactant molecules. With the BF3-catalyzed reactions, the complete regioselectivity observed experimentally has well been reproduced by theoretical calculation and these results originate probably from blue-shifting C-H...F hydrogen bond interaction in some transition states.

FlexMEMS-enabled hetero-integration for monolithic FBAR-above-IC oscillators

In this work,a monolithic oscillator chip is heterogeneously integrated by a film bulk acoustic resonator(FBAR)and a complementary metal-oxide-semiconductor(CMOS)chip using FlexMEMS technology.In the 3 D-stacked integrated chip,the thin-film FBAR sits directly over the CMOS chip,between which a 4μm-thick SU-8 layer provides a robust adhesion and acoustic reflection cavity.The proposed system-on-chip(SoC)integration features a simple fabrication process,small size,and excellent performance.The oscillator outputs 2.024 GHz oscillations of-13.79 dB m and exhibits phase noises of-63,-120,and-136 dB c/Hz at 1 kHz,100 kHz,and far-from-carrier offset,respectively.FlexMEMS technology guarantees compact and accurate assembly,process compatibility,and high performance,thereby demonstrating its great potential in SoC hetero-integration applications.

Synthesis and Crystal Structure of a New μ-Oxamide Trimeric Hetero-tetranuclear Complex

A novel oxamide-bridged trimeric tetranuclear complex 1 incorporating a macro- cyclic oxamide of formula {[(CuL)3Mn](ClO4)2}3 (macrocyclic oxamide L = 2,3-dioxo-5,6,14,15- dibenzo-1,4,8,12-tetraazacyclopentadeca-7,12-diene) was prepared and structurally characterized. The compound [(CuL)3Mn](ClO4)2 crystallizes in the trigonal system, space group P 3 with a = 22.434(17), b = 22.434(17), c = 18.82(2) ?, α = β = 90, γ = 120o, V = 8203(13) ?3, Z = 6, Dc = 1.751g/cm3, μ(MoKα) = 1.557, F(000) = 4392, the final R = 0.083 and wR = 0.1727 for 9604 obser- ved reflections with I > 2σ(I). The single-crystal X-ray analysis shows that 1 is a trimeric complex. There are three similar constitutes, dissimilar conformations and asymmetrically independent ‘building-block’ [(CuL)3Mn] in one crystal cell of the title complex 1.

Analysis on high speed response of a uni-traveling-carrier double hetero-junction phototransistor

In this paper, the positive influence of a uni-traveling-carrier （UTC） structure to ease the contract between the respon- sivity and working speed of the InP-based double hetero-junction phototransistor （DHPT） is illustrated in detail. Different results under electrical bias, optical bias or combined electrical and optical bias are analyzed for an excellent UTC-DHPT performance. The results show that when the UTC-DHPT operates at three-terminal （3T） working mode with combined electrical bias and optical bias in base, it keeps a high optical responsivity of 34.72 A/W and the highest optical transition frequency of 120 GHz. The current gain of the 3T UTC-DHPT under 1.55-μm light illuminations reaches 62 dB. This indicates that the combined base electrical bias and optical bias of 3T UTC-DHPT can make sure that the UTC-DHPT provides high optical current gain and high optical transition frequency simultaneously.

A(3,4)-Connected 3D Heteronuclear Framework with Three Kinds of Discrete Cadmium(Ⅱ) Ions: Synthesis,Crystal Structure and Luminescence Property

A novel 3D hetero-nuclear framework,namely [K_2Cd_5（Hbptc）_4（H_2O）_（12）·12H_2O]_n（1,H4 bptc = biphenyl-2,3,3？,5？-tetracarboxylic acid）,was obtained by hydrothermal reaction. X-ray singlecrystal structure analysis reveals that polymer 1 crystallizes in orthorhombic,space group Pbcn with a = 26.6152（13）,b = 11.7449（5）,c = 29.5923（14） ？,V = 9250.3（7） ？~3,C_（64）H_（76）Cd_5K_2O_（56）,Mr = 2381.44,Dc = 1.710 g/cm^3,μ（MoK α） = 1.323 mm^（-1）,F（000） = 4744,Z = 4,the final R = 0.0668 and wR = 0.1135 for 10613 observed reflections（I 〉 2σ（I））. Polymer 1 displays a 3D network that is built on the unprecedented heterobimetallic [Cd_3Cd_2K] molecular building block with a（3,4）-connected（6·8·8）2（6·6·82·82·126·126） topology which represents a rare 2-fold interpenetrating 3D framework topology network. The luminescence analyses reveal that polymer 1 shows obvious emission at room temperature in the solid state. In addition,it was also characterized by elemental,IR spectra and TG analyses.

有机半导体的异质结(Hetero-junction)问题

有机异质结在有机电子器件中起到十分重要的作用,它不仅对有机器件中载流子的运动起到控制和调节的作用,而且对器件的基本功能特征,诸如光-电转换,电-光转换器件中某些要害步骤(如电子转移,能量转移等)起到重要的作用.本文扼要地从层间能量关系对有关有机异质结进行分类和讨论,并对异质结的界面能量关系中存在的问题及其进展作了介绍.显然,这将对有关器件设计的思路有所帮助.

A Rule to Design High Spin Molecules with Hetero spin Centers

The series of biradicals with m phenylene coupling unit and hetero spin centers were calculated compared with those possessing homo spin centers using AM1 CI method. A simple rule was proposed to design high spin molecules with ferromagnetic coupling unit and hetero spin centers. Two neutral (or charged) hetero spin centers resulted in high spin ground state, one neutral and another charged hetero spin centers correspond to low spin ground state. The latter was ascribed to the huge splitting of two partially occupied molecular orbitals.

Vertical polarization-induced doping InN/InGaN heterojunction tunnel FET with hetero T-shaped gate

A novel vertical InN/InGaN heterojunction tunnel FET with hetero T-shaped gate as well as polarization-doped source and drain region(InN-Hetero-TG-TFET)is proposed and investigated by Silvaco-Atlas simulations for the first time.Compared with the conventional physical doping TFET devices,the proposed device can realize the P-type source and N-type drain region by means of the polarization effect near the top InN/InGaN and bottom InGaN/InN heterojunctions respectively,which could provide an effective solution of random dopant fluctuation(RDF)and the related problems about the high thermal budget and expensive annealing techniques due to ion-implantation physical doping.Besides,due to the hetero T-shaped gate,the improvement of the on-state performance can be achieved in the proposed device.The simulations of the device proposed here in this work show ION of 4.45×10^(-5)A/μm,ION/IOFF ratio of 10^(13),and SS_(avg)of 7.5 mV/dec in InN-Hetero-TG-TFET,which are better than the counterparts of the device with a homo T-shaped gate(InN-Homo-TG-TFET)and our reported lateral polarization-induced InN-based TFET(PI-InN-TFET).These results can provide useful reference for further developing the TFETs without physical doping process in low power electronics applications.

Rectifying barrier at GaN/SiC hetero-junction studied with positron annihilation spectroscopy

Positron annihilation spectroscopy on GaN films grown on SiC substrate with MBE are presented. It is shown that the GaN/SiC interface is rectifying towards positrons, such that positrons can only travel from SiC to GaN and not vice versa. Potential steps seen by the positron at the GaN/SiC interface are calculated from experimental values of electron and positron work function. This “rectifying” effect has been successfully mimicked by inserting a thin region of very high electric field in the Variable Energy Positron Fit （VEPF） analysis. The built-in electric field is attributed to different positron affinities, dislocation and/or interface defects at the GaN/SiC interface.

Mannich-Type Reactions of Aldimines and Hetero Diels-Alder Reactions of Aldehydes Catalyzed by Anion-Type Lewis Bases Derived from a Single Molecule

Mannich-type reactions of aldimines with silyl enolates and hetero Diels-Alder reactions of aldehydes with Danishef-sky’s diene in the presence of anion catalysts derived from proline were performed to afford the corresponding products in high yields.

MOCVD Growth of Doped GaAs/AlGaAs Quantum Heterostructures

The influences of growth techniques of AP-MOCVD GaAs/AlGaAs silicon-doped multi-quantum wells (MQWs), heterostructure bipolar transistors (HBTs), double barrier resonant tunneling diodes(DBRTDs) on their structures and performances were studied. Continuously grown MQWs, that is, no growth interruption at the heterointerfaces, shown blue-shifted, narrower and stronger photoluminescence(PL) compared with interruptedly grown ones.TEM examination of the interrupted interfaces revealed a bright line corresponding to the compositional fluctuation and impurity adsorption, and indicated noncommutative structures of AlGaAs/GaAs and GaAs/AlGaAs interfaces. High performance HBTs and DBRTDs were obtained by continuously grown method while growth interruption caused performance degradation. It was concluded that growth interruption may cause accumulation of residua1 impurities in the ambient as well as compositional fluctuation while continuous growth at very low growth rates can overcome such problems.

Thermoelectric-transport in metal/graphene/metal hetero-structure

We investigate the thermoelectric-transport properties of metal/graphene/metal hetero-structure. We use a single band tight-binding model to prcsent the two-dimensional electronic band structure of graphene. Using the LandauerButticker formula and taking the coupling between graphene and the two electrodes into account, we can calculate the thermoelectric potential and current versus temperature. It is found that in spite of metal electrodes, the carrier type of graphene determines the electron motion direction driven by the difference in temperature between the two electrodes, while for n type graphene, the electrons move along the thermal gradient, and for p type graphene, the electrons move against the thermal gradient.

HOMO- AND COPOLYMERIZATION OF ETHYLENE CATALYZED BY ANSA-METALLOCENES WITH DOUBLY HETERO-BRIDGES

Three ansa-metallocenes(Me_2C)(Me_2Si)Cp_2TiCl_2(1),[(CH_2)_5C](Me_2Si)Cp_2TiCl_2 (2)and (Me_2C)(Me_2Si)Cp_2ZrCl_2 (3)with larger dihedral angles and longer distance from metal to the center of Cp planes were synthesized and used as catalysts for ethylene polymerization in the presence of methylaluminoxane (MAO).In the case of ethylene polymerization,compared the feature structures of unbridged metallocenes, singly bridged metallocenes and doubly bridged metallocenes 1,2,3,there exhibit the relationship bet...