电子纸技术及其研究现状与展望

就电子纸显示的基本原理和技术特征及其研究进展几个方面做了综合评述 ,并展望了电子纸在未来显示技术和设备中的应用前景。     

Electrical properties of (Bi3.5La0.5)Ti3O12 thin-films prepared by liquid source misted chemical deposition

The ((Bi_3.5La_0.5)Ti₃O₁₂(BLT) thin-films used in this study were fabricated on a Pt(111)/SiO₂/Si(100) substrate by a Liquid Source Misted Chemical Deposition (LSMCD) technique. X-ray diffraction patterns showed that the BLT films were crystallized and no other phases were observed when annealed above 650 ‡C. Grain size and remnant polarizations increased with increase in the annealing temperature, while leakage current densities decreased. The remnant polarizations (Pr) increased from 2.0 to 4.8 and 19.0 μC/cm2 with increase in the annealing temperature from 650 to 700 and 750 ‡C, respectively. The BLT films annealed at 700 ‡C in O₂ showed a good fatigue resistance of reduced polarization by 10% after 10⁹ switching cycles when 9 V of bipolar voltage was applied at a frequency of 40 kHz.     

Straightforward modeling of dynamic I–V characteristics for microwave FETs

This work presents a straightforward approach aimed at modeling the dynamic I–V characteristics of microwave active solid‐state devices. The drain‐source current generator represents the most significant source of nonlinearity in a transistor and, therefore, its correct modeling is fundamental to predict accurately the current and voltage waveforms under large‐signal operation. The proposed approach relies on using a small set of low‐frequency time‐domain waveform measurements combined with numerical optimization‐based estimation of the nonlinear model parameters. The procedure is applied to a gallium nitride HEMT and silicon FinFET. The effectiveness of the modeling procedure in terms of prediction accuracy and generalization capability is demonstrated by validation of the extracted models under operating conditions different than the ones used for the parameters estimation. Good agreement between measurements and model simulations is achieved for both technologies and in both low‐ and high‐frequency range. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:109–116, 2014.     

The influence of preparation conditions on electrochemical properties of LiNi0.5Mn1.5O4 thin film electrodes by PLD

LiNi_0.5Mn_1.5O₄ thin films were prepared by pulsed laser deposition (PLD) on stainless steel substrates. The growth of the films has been studied as a function of substrate temperature and oxygen partial pressure in deposition, using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). Electrochemical properties of LiNi_0.5Mn_1.5O₄ thin film cathodes were investigated using cyclic voltammetry and galvanostatic charge/discharge against a lithium anode. The initial capacity and capacity retention of the films are highly dependent on the crystallinity and purity of the films. LiNi_0.5Mn_1.5O₄ thin films grown at 600 °C in an oxygen partial pressure of 200 mTorr are well crystallized with high purity, exhibiting excellent capacity retention between 3 and 5 V with a LiPF₆-based electrolyte.     

基于聚合物电介质的并五苯场效应晶体管

采用顶接触结构分别在SiO2、聚甲基丙烯酸甲酯(PMMA)绝缘层上制备了以并五苯为有源层的两种有机场效应晶体管(OFET),其中SiO2绝缘层采用热生长法制备,PMMA绝缘层采用溶液旋涂法制备。与常规基于无机绝缘层的器件相比,采用聚合物为绝缘层后,不但器件的制作工艺简化和成本降低,而且器件性能大幅提高,经测试,器件的迁移率提到0.153cm2/Vs,而阈值电压降低6V。采用原子力显微镜(AFM)、X射线衍射(XRD)等对器件性能提高的原因进行了详细分析。     

Proton irradiation damage mechanism of the InAlAs／InGaAs／InAlAs quantum well

InP-based high electron mobility transistors (HEMT) have shown a great potential for national defense and satellite radar in space radiation environment applications. This paper studies the proton radiation damage mechanism of its critical structure InAlAs／InGaAs／InAlAs quantum well. The proton projection range and vacancy defect information are obtained at different incident proton energies of 50keV, 75keV and 200keV by SRIM software. With the increase of proton energy, the proton injection depth is increasing and eventually protons pass through the material layers. Besides, the proton radiation induced vacancy defects numbers around hetero-junction increase first and decrease subsequently, and As vacancies are the main proton radiation induced defects. In addition, non-ionizing energy loss (NIEL) of In_0.52Al_0.48As and In_0.53Ga_0.47As material is computed under different incident proton energies by the analytical model. The change trend of NIEL is identical to the induced vacancy numbers, namely, NIEL first increases and then decreases as the incident proton energy increases. Finally the degrading effect of the radiation-induced As defect is detected in the two-dimensional electron gas in the quantum well, which confirms that the major proton radiation damage mechanism of the quantum well is the induced vacancy defects by NIEL.     

电磁超声相控阵激励源高频隔离驱动电路

为了进一步提高电磁超声相控阵激励源的工作效率,基于半桥拓扑放大结构提出了一种电磁超声相控阵激励源高频隔离驱动电路的设计方法.根据金属氧化物半导体场效应晶体管(metal oxide semiconductor field effect transistor,MOSFET)的简化模型,分析了MOSFET在开通和关断过程中的开关损耗,从而给出了高频隔离驱动电路所必须满足的条件.通过采用光纤器件隔离脉冲信号和DC-DC隔离电源对参考电位进行转换,有效解决了驱动电路的高频"浮栅"问题,并利用RC微分电路和施密特反相器设计了驱动信号死区时间可调电路.实验结果表明:设计的驱动电路能够输出频率为1.1 MHz、死区时间为0.32μs、驱动电压为18.8 V、占空比为26%的互补驱动信号,并且在驱动MOSFET栅极的实际应用中,有效降低了功率开关管的功率损耗.     

Thin‐film transistor mobility limits considerations

The mobility limiting scattering mechanisms for amorphous semiconductors and polar polycrystalline semiconductors are studied in the context of developing new high‐performance thin‐film transistor (TFT) channel layer materials for large‐area electronics. A physics‐based model for carrier transport in an amorphous semiconductor is developed to estimate the mobility limits of amorphous semiconductor TFTs. The model involves band tail state trapping of a diffusive mobility. Simulation reveals a strong dependence on the band tail density of states. This consideration makes it difficult to realize a high‐performance p‐type oxide TFT. A polar crystalline semiconductor may offer a higher mobility but is fundamentally limited by polar optical phonon scattering. Any crystalline TFT channel layer for practical large‐area applications will not be a single crystal but polycrystalline, and therefore, grain size and grain boundary‐dependent scattering will further degrade the transport properties.     

Instability of light illumination stress on amorphous In–Ga–Zn–O thin‐film transistors

Amorphous In–Ga–Zn–O thin‐film transistors (TFTs) have attracted increasing attention due to their electrical performance and their potential for use in transparent and flexible devices. Because TFTs are exposed to illumination through red, green, and blue color filters, wavelength‐varied light illumination tests are required to ensure stable TFT characteristics. In this paper, the effects of different light wavelengths under both positive and negative V_GS stresses on amorphous In–Ga–Zn–O TFTs are investigated. The TFT instability that is dependent on optical and electrical stresses can be explained by the charge trapping mechanism and interface modification.     

基于ISFET的农药检测生物传感技术

随着微电子、生物技术的发展,离子敏场效应晶体管(ISFET)生物传感技术已应用于农药检测,并显示出较好的优越性,而我国对基于ISFET的农药检测生物技术研究尚未展开。简单介绍了基于IS-FET的生物传感器的结构、原理,重点探讨了其在农药检测方面的研究应用,分析了ISFET生物传感器存在的问题与未来的发展。