Boosted Lithium-Ion Transport Kinetics in n-Type Siloxene Anodes Enabled by Selective Nucleophilic Substitution of Phosphorus

Doped two-dimensional(2D)materials hold significant promise for advancing many technologies,such as microelectronics,optoelectronics,and energy storage.Herein,n-type 2D oxidized Si nanosheets,namely n-type siloxene(n-SX),are employed as Li-ion battery anodes.Via thermal evaporation of sodium hypophosphite at 275℃,P atoms are effectively incorporated into siloxene(SX)without compromising its 2D layered morphology and unique Kautsky-type crystal structure.Further,selective nucleophilic substitution occurs,with only Si atoms being replaced by P atoms in the O_(3)≡Si-H tetrahedra.The resulting n-SX possesses two delocalized electrons arising from the presence of two electron donor types:(i)P atoms residing in Si sites and(ii)H vacancies.The doping concentrations are varied by controlling the amount of precursors or their mean free paths.Even at 2000 mA g^(-1),the n-SX electrode with the optimized doping concentration(6.7×10^(19) atoms cm^(-3))delivers a capacity of 594 mAh g^(-1) with a 73%capacity retention after 500 cycles.These improvements originate from the enhanced kinetics of charge transport processes,including electronic conduction,charge transfer,and solid-state diffusion.The approach proposed herein offers an unprecedented route for engineering SX anodes to boost Li-ion storage.

Ta_2O_5-PMMA复合栅绝缘层对OFETs性能的影响（英文）

选用五氧化二钽(Ta_2O_5)-聚甲基丙烯酸甲酯(PMMA)复合材料作为栅绝缘层制备了并五苯有机场效应晶体管(OFETs)。通过在Ta_2O_5表面旋涂一层PMMA可以降低栅绝缘层的表面粗糙度,增大其场效应晶体管的迁移率。研究了厚度在20~60 nm范围内的PMMA对复合绝缘层表面形貌、粗糙度以及器件电学性能的影响。结果表明,当PMMA厚度为40 nm时,器件的电学性能最佳。与单一的Ta_2O_5栅绝缘层器件相比,其场效迁移率由4.2×10^(-2)cm^2/(V·s)提高到0.31 cm^2/(V·s);栅电压增加到-20 V时,开关电流比由2.9×10~2增大到2.9×10~5。

高性能柔性OFET器件最新进展研究

有机场效应晶体管,因其质轻价廉且与柔性衬底兼容等优点,广泛应用于传感器阵列,平板显示器和射频识别等许多领域。为了获得迁移率高、空气稳定性好、机械柔韧性佳的高性能柔性OFET,本文以对器件性能影响较为显著的关键因素为出发点,阐述了柔性OFET器件衬底材料、绝缘层材料、电极材料及制备工艺的最新进展情况。结果表明,全有机柔性OFET器件具备低压操作,良好电荷捕获能力,弯曲时器件特性稳定等优点,适合大规模商业化使用。

基于有机场效应晶体管的可穿戴柔性监测设备在生物医学领域的研究现状

介绍了基于有机场效应晶体管(organic field effect transistor,OFET)技术的柔性半导体器件的工作原理和发展概况,综述了基于OFET的生物力学监测设备、文身生物监测设备、细胞检测设备等可穿戴柔性监测设备的研究现状,分析了基于OFET的可穿戴柔性监测设备存在的不足,指出了微型化、个性化、多元化等是未来基于OFET的可穿戴柔性监测设备的发展方向。

Noticeable positive Doppler effect on optical bistability in an N-type active Raman gain atomic system

We theoretically investigate the Doppler effect on optical bistability in an N-type active Raman gain atomic system inside an optical ring cavity. It is shown that the Doppler effect can greatly enhance the dispersion and thus create the bistable behaviour or greatly increase the bistable region, which has been known as the positive Doppler effect on optical bistability. In addition, we find that a positive Doppler effect can change optical bistability from the hybrid dispersion-gain type to a dispersive type.

Analytical Descriptions of Magnetic Properties and Magnetoresistance in n-Type HgCr_2Se_4

We present a detailed investigation of magnetic properties of colossal magnetoresistance material HgCr2Se4. While spontaneous magnetization and zero-field magnetic susceptibility are found to follow asymptotic scaling laws for a narrow range of temperatures near the critical point, two methods with connections to the renormalization group theory provide analytical descriptions of the magnetic properties for much wider temperature ranges. Based on this, an analytical formula is obtained for the temperature dependence of the low field magnetoresistance in the paramagnetic phase.

New CMOS compatible super-junction LDMOST with n-type buried layer

A new super-junction lateral double diffused MOSFET （LDMOST） structure is designed with n-type charge compensation layer embedded in the p^--substrate near the drain to suppress substrate-assisted depletion effect that results from the compensating charges imbalance between the pillars in the n-type buried layer. A high electric field peak is introduced in the surface by the pn junction between the p^--substrate and n-type buried layer, which given rise to a more uniform surface electric field distribution by modulation effect. The effect of reduced bulk field （REBULF） is introduced to improve the vertical breakdown voltage by reducing the high bulk electric field around the drain, The new structure features high breakdown voltage, low on-resistance and charges balance in the drift region due to n-type buried layer.

Uniaxial stress influence on lattice,band gap and optical properties of n-type ZnO:first-principles calculations

The lattice, the band gap and the optical properties of n-type ZnO under uniaxial stress are investigated by first- principles calculations. The results show that the lattice constants change linearly with stress. Band gaps are broadened linearly as the uniaxial compressive stress increases. The change of band gap for n-type ZnO comes mainly from the contribution of stress in the c-axis direction, and the reason for band gap of n-type ZnO changing with stress is also explained. The calculated results of optical properties reveal that the imaginary part of the dielectric function decreases with the increase of uniaxial compressive stress at low energy. However, when the energy is higher than 4.0 eV, the imaginary part of the dielectric function increases with the increase of stress and a blueshift appears. There are two peaks in the absorption spectrum in an energy range of 4.0-13.0 eV. The stress coefficient of the band gap of n-type ZnO is larger than that of pure ZnO, which supplies the theoretical reference value for the modulation of the band gap of doped ZnO.

Hot-Carrier Effects on Total Dose Irradiated 65 nm n-Type Metal-Oxide-Semiconductor Field-Effect Transistors

The influence of total dose irradiation on hot-carrier reliability of 65 nm n-type metal-oxide-semiconductor field- effect transistors （nMOSFETs） is investigated. Experimental results show that hot-carrier degradations on ir- radiated narrow channel nMOSFETs are greater than those without irradiation. The reason is attributed to radiation-induced charge trapping in shallow trench isolation （STI）. The electric field in the pinch-off region of the nMOSFET is enhanced by radiation-induced charge trapping in STI, resulting in a more severe hot-carrier effect.

Recent development of n-type thermoelectric materials based on conjugated polymers

Thermoelectric(TE)materials based on conjugated polymers have received much attention due to their great advantages of solution processibility,light weight,flexibility,and low thermal conductivity.These advantages make them potential candidates for large-area,low-cost and low-power TE applications.Both efficient p-type and n-type conjugated polymers with high and comparable thermoelectric performance are required for practical TE applications.However,due to the inefficient n-doping efficiency and unstable electron transport of most n-type conjugated polymers,the TE performance of n-type polymers is much poorer than that of their p-type counterparts,impeding the development of polymer TE materials.Great efforts have been made to address the low ndoping efficiency and TE performance of n-type polymers,including the chemical modification of traditional ntype polymers,the design of new n-type conjugated polymers,and the development of more efficient n-dopants,as well as doping engineering.Nowadays,the TE performance of n-type polymers has been greatly improved,indicating a bright future for polymer TE materials.In this review,we summarize the recent progress made on ntype polymer TE materials,mainly focusing on the structure-performance relationships based on promising n-type polymers for TE applications.This review aims to provide some guidelines for future material design.

新型电极材料在N型OFET中的应用

相比于无机场效应晶体管,有机场效应晶体管(OFET)具有制备工艺简单、成本低、柔性、透明等优点,在柔性电子产品、可穿戴器件等领域中有广泛用途。电极作为OFET器件的一个重要组成部分,其影响OFET器件的整体性能。为了提升电极性能,一方面可以对金属电极进行修饰,另一方面可以使用聚合物等新材料来制作OFET电极。围绕新型电极材料在N型OFET中的应用展开综述。首先,介绍OFET的一般器件结构。接着依次介绍了修饰金属电极、聚合物电极、碳基电极、无机化合物电极和纳米线电极的N型OFET进展。最后,总结全文,并对OFET新型电极材料的未来发展做出了展望。

Experimental Investigation of the Electromagnetically Induced-Absorption-Like Effect for an N-Type Energy Level in a Rubidium BEC

We study the electromagnetically induced-absorption-like(EIA-like) effect for an n-type system in an ^(87)Rb Bose–Einstein condensate(BEC) using the absorption imaging technique for coupling and driving lasers operating at the D_1 and D_2 lines of ^(87)Rb. The coherent effect is probed by measuring the number of atoms remaining after the BEC is exposed to strong driving fields and a weak probe field. The absorption imaging technique accurately reveals the EIA-like effect of the n-type system. This coherent effect in an n-type system is useful for optical storage, tunable optical switching, and so on.

N-type core-shell heterostructured Bi2S3@Bi nanorods/polyaniline hybrids for stretchable thermoelectric generator

With the growing need on distributed power supply for portable electronics,energy harvesting from environment becomes a promising solution.Organic thermoelectric(TE)materials have advantages in intrinsic flexibility and low thermal conductivity,thus hold great prospect in applications as a flexible power generator from dissipated heat.Nevertheless,the weak electrical transport behaviors of organic TE materials have severely impeded their development.Moreover,compared with p-type organic TE materials,stable and high-performance n-type counterparts are more difficult to obtain.Here,we developed a n-type polyaniline-based hybrid with core-shell heterostructured Bi;S;@Bi nanorods as fillers,showing a Seebeck coefficient-159.4μV/K at room temperature.Further,a couple of n/p legs from the PANI-based hybrids were integrated into an elastomer substrate forming a stretchable thermoelectric generator(TEG),whose function to output stable voltages responding to temperature differences has been demonstrated.The in situ output performance of the TEG under stretching could withstand up to 75%elongation,and stability test showed little degradation over a one-month period in the air.This study provides a promising strategy to develop stable and high thermopower organic TEGs harvesting heat from environment as long-term power supply.

n-type ZnS used as electron transport material in organic light-emitting diodes

This paper reports on the n-type ZnS used as electron transport layer for the organic light-emitting diodes （OLEDs）. The naphthyl-substituted benzidine derivative （NPB） and tris （8-hydroxyquinoline） aluminium （Alq3） are used as the hole transport layer and the emitting layer respectively. The insertion of the n-type ZnS layer enhances the electron injection in the OLEDs. The study was carried out on OLEDs of structures： indium-tin-oxide （ITO）/NPB/Alq3/ZnS/LiF/AL, ITO/NPB/Alq3/LiF/AL and ITO/NPB/Alq3/AL. The luminance and efficiency of the device containing this electron transport layer are increased significantly over those obtained from conventional devices due to better carrier balance.

Nonlinear optical properties in n-type quadrupleδ-doped GaAs quantum wells

The effects of the interlayer distance on the nonlinear optical properties of n-type quadrupleδ-doped GaAs quantum well were theoretically investigated.Particularly,the absorption coefficient and the relative refraction index change were determined.In the effective mass approach and within the framework of the Thomas-Fermi theory,the Schrodinger equation was resolved.Thereby,the subband energy levels and their respective wave functions were calculated.The variations in the nonlinear optical properties were determined by using the density matrix solutions.The achieved results demonstrate that the interlayer distance causes optical red-shift on nonlinear optical properties.Therefore,it can be deduced that the suitably chosen interlayer distance can be used to tune optical properties within the infrared spectrum region in optoelectronic devices such as far-infrared photo-detectors,high-speed electronic-optical modulators,and infrared lasers.

Boron implanted emitter for n-type silicon solar cell

The effects of ion doses on the properties of boron implanted Si for n-type solar cell application were investigated with doses ranging from 5×10^14cm^-2 to 2×10^15cm^-2 and a subsequent two-step annealing process in a tube furnace.With the help of the TCAD process simulation tool, knowledge on diffusion kinetics of dopants and damage evolution was obtained by fitting SIMS measured boron profiles. Due to insufficient elimination of the residual damage, the implanted emitter was found to have a higher saturation current density（J0e） and a poorer crystallographic quality. Consistent with this observation, V oc, J sc, and the efficiency of the all-implanted p^＋–n–n^＋solar cells followed a decreasing trend with an increase of the implantation dose. The obtained maximum efficiency was 19.59% at a low dose of 5×10^14cm^-2. The main efficiency loss under high doses came not only from increased recombination of carriers in the space charge region revealed by double-diode parameters of dark I–V curves, but also from the degraded minority carrier diffusion length in the emitter and base evidenced by IQE data. These experimental results indicated that clusters and dislocation loops had appeared at high implantation doses, which acted as effective recombination centers for photogenerated carriers.

Thermoelectric Properties of n-type Poly(nickel 1,1,2,2-ethenetetrathiolate)Prepared by a New One-step Solvothermal Method

Poly(nickel 1,1,2,2-ethenetetrathiolate)(poly[Na_(x)(Ni-ett)])is one of the most promising n-type organic thermoelectric materials which can be used in wearable devices.However,the conventional solution method is time-consuming and the prepared poly[Na_(x)(Ni-ett)]usually has poor crystallinity,which does not benefit for achieving high thermoelectric performance.Here,a new one-step solvothermal method under the high reaction temperature and high vapor pressure was developed to prepare poly[Na_(x)(Ni-ett)]with a quite short period.The experimental results show crystallinity and electrical conductivity are greatly enhanced as compared with those prepared by conventional solution method.As a result,a maximum ZT value of 0.04 was achieved at 440 K,which is about four times of the polymer prepared by the conventional solution method.This study may provide a new route to enhance the TE properties of n-type organic thermoelectric materials.

Annealing Effects on Electrical Properties and Interfacial Reactions of Ni/Cu Schottky Rectifiers on n-Type InP

We report on the effect of annealing temperature on electrical, interfacial reactions and surface morphological properties of Ni/Cu Schottky contacts on n-type InP. The extracted barrier height of as-deposited Ni/Cu Schottky contact is 0.59 eV (I-V) respectively. The high-quality Schottky contact with barrier height and ideality factor of 0.65 eV (I-V) and 1.15 respectively, can be obtained after annealing at 300℃ for 1 min in a nitrogen atmosphere. However, annealing at 400℃, results the decrease in the barrier height to 0.54 eV (I-V). From the above observations, it is observed that Ni/Cu Schottky contact exhibited excellent electrical properties after annealing at 300℃. Hence, the optimum annealing temperature for the Ni/Cu Schottky contact is 300℃. Furthermore, Cheung’s functions is used to extract the diode parameters including ideality factor, barrier height and series resistance. According to the XRD analysis, the formation of the indium phases at the Ni/Cu/n-InP interface could be the reason for the increase in the barrier height at annealing temperature 300℃. Further, the degradation of the barrier heights after annealing at 400℃ may be due to the formation of phosphide phases at the Ni/Cu/n-InP interface. Scanning electron microscopy (SEM) results show that the overall surface morphology of the Ni/Cu Schottky contact is reasonably smooth.

Anomalous Channel Length Dependence of Hot-Carrier-Induced Saturation Drain Current Degradation in n-Type MOSFETs

The dependencies of hot-carrier-induced degradations on the effective channel length Lch,eff are investigated for n-type metal-oxide-semiconductor field effect transistor （MOSFETs）. Our experiments find that, with decreasing Lch,eff, the saturation drain current （Iasat ） degradation is unexpectedly alleviated. The further study demonstrates that the anomalous Lch,eff dependence of Idsat degradation is induced by the increasing influence of the substrate current degradation on the lazar degradation with Lch,eff reducing.

Spin Dynamics in Ferromagnet/10-nm-Thick N-Type GaAs Quantum Well Junctions

Spin dynamics in several different types of ferromagnetic metal （FM）/10-nm-thick n-type GaAs quantum well （QW） junctions is studied by means of time-resolved Kerr rotation measurements. Compared with the MnGa/insitu doped lO-nm-thick n-type GaAs QW junction, the spin lifetime of the MnGa/modulation-doped 10-nm-thick n-type GaAs QW junction is shorter by a factor of 6, consistent with the D＇yakonov Perel＇ spin relaxation mechanism. Meanwhile, compared with the spin lifetime of the MnAs/in-situ doped 10-nm-thick n-type GaAs QW junction, the MnGa/in-situ doped 10-nm-thick n-type GaAs QW junction is of a spin lifetime longer by a factor of 4.2. The later observation is well explained by the Rashba effect in the presence of structure inversion asymmetry, which acts directly on photo-excited electron spins. We demonstrate that MnGa-like FM/in-situ doped 10-nm-thick n-type GaAs QW junctions, which possess relatively low interfaciai potential barriers, are able to provide long spin lifetimes.