锂离子电池用保护电路的低功耗设计

设计了一种单节锂离子电池保护电路。分析了系统的特点和应用要求,提出了采用亚阈值电路和由内部数字信号来控制模拟电路工作状态的方法,优化了系统的功耗。电路采用0．6肛mUMC数字电路工艺实现。HSPICE模拟结果表明,该电路不仅能满足锂离子电池应用中的保护要求,而且具有较低的电流功耗,在正常和Standby模式下。系统消耗电流分别3．23μA和0．15μA。     

Radiative autoionization--A proposal for the construction of short-wavelength lasers

Radiatsive autoionization (RA) is a spontaneous decay mechanism of highly excited states, whereby the atom or molecule makes a radiative bound- (or quasi-bound-) free transition, emitting a photon and an electron at the same time. Calculations show that, for each transition, the intensity of the emitted radiation peaks on the short-wavelength side. Since RA involves a final empty state, population inversion is achieved once the initial state is populated. The basic lasing condition can thus be satisfied automatically. The phenomenon is analogous to the radiative dissociation process which is the physical mechanism for the excimer laser. Examples are given for the H- and He 2p²³p, He- and Li 2p³⁴S0, Li and Be+ 1s2p²²p, He 2p3p¹P, and 2p3d¹D⁰, as well as for the Li 1s2s2p⁴P⁰state which undergoes relativistic RA.     

用于测辐射热计热敏材料的多晶锗硅薄膜的研究

根据测辐射热计对热敏感材料的要求,采用超高真空化学气相淀积(UHVCVD)法制备出多晶Si0.7Ge0.3薄膜,研究了B离子注入剂量、退火工艺与电导率和电阻温度特性的相关性,因此确定出了最佳的工艺条件,并利用其制备出了探测率高达3.75×108cmHz1/2.W-1的测辐射热计。     

Study on ALD In2S3/Cu(In,Ga)Se2 interface formation

The formation of the interface between In₂S₃ grown by atomic layer deposition (ALD) and co‐evaporated Cu(In,Ga)Se₂ (CIGS) has been studied by X‐ray and UV photoelectron spectroscopy. The valence band offset at 160°C ALD substrate temperature was determined as −1·2±0·2 eV for CIGS deposited on soda‐lime glass substrates and −1·4±0·2 eV when a Na barrier substrate was used. Wavelength dependent complex refractive index of In₂S₃ grown directly on glass was determined from inversion of reflectance and transmittance spectra. From these data, an indirect optical bandgap of 2·08±0·05 eV was deduced, independent of film thickness, of substrate temperature and of Na content. CIGS solar cells with ALD In₂S₃ buffer layers were fabricated. Highest device efficiency of 12·1% was obtained at a substrate temperature of 120°C. Using the bandgap obtained for In₂S₃ on glass and a 1·15±0·05 eV bandgap determined for the bulk of the CIGS absorber, the conduction band offset at the buffer interface was estimated as −0·25±0·2 eV (−0·45±0·2 eV) for Na‐containing (Na‐free) CIGS. Copyright © 2005 John Wiley & Sons, Ltd.     

一种用于数模转换器的电流-电压转换电路

介绍了一种用于数模转换器的电流 电压转换电路。在数模转换器的负载电阻片内集成的情况下 ,利用文中提出的电流 电压转换电路 ,数模转换器实现了要求的宽摆幅电平输出 (全“0”输入时 ,输出低电平 - 3V ;全“1”输入时 ,输出高电平 3 5V)。整个数模转换器电路用 1 2 μm双层金属双层多晶硅n阱CMOS工艺实现。其积分非线性误差为 0 4 5个最低有效位 (LSB) ,微分非线性误差为 0 2LSB ,满摆幅输出的建立时间小于 1μs。该数模转换器使用± 5V电源 ,功耗约为 30mW ,电路芯片面积为 0 4 2mm2 。     

X波段宽带功率放大器

介绍了８～１２ＧＨｚ宽带功率放大器的设计、制作。放大器的主要技术指标：工作频率８～１２ＧＨｚ，增益≥２３ｄＢ，１ｄＢ压缩输出功率≥２７ｄＢｍ，输入输出驻波比≤２∶１。     

Local Structure and Chemistry of C‐Doped ZnO@C Core–Shell Nanostructures with Room‐Temperature Ferromagnetism

A superior approach is presented to study quantitatively fine structure of C‐doped ZnO nanostructure using transmission electron microscopy (TEM) from which the role of carbon in ZnO crystal to form ferromagnetism is revealed at the first time. Electron diffraction in TEM shows Wurtzite structure in the nanoparticles with lattice parameters (a = 0.327 ± 0.03 nm and c = 0.529 ± 0.04 nm) slightly different from the original structure. Interestingly, the Zn–C bonding with a bonding length of 2.58 Å is experimentally determined using atomic pair distribution function (PDF) calculated from electron diffraction data. Together with other bondings, such as C–C, Zn–O obtained from the PDF, this demonstrates migration of C atoms into ZnO crystal to substitute O vacancies. This is furthermore visualized by high‐resolution TEM imaging and elemental mapping, and strongly supports the proposal of origin of ferromagnetism in the C‐doped ZnO nanoparticles where the s–p and p–p hybridizations formed by C2p–Zn4s, and O2p–C2p orbitals are believed to cause ferromagnetism.     

Stack system of PECVD amorphous silicon and PECVD silicon oxide for silicon solar cell rear side passivation

A stack of hydrogenated amorphous silicon (a‐Si) and PECVD‐silicon oxide (SiO_x) has been used as surface passivation layer for silicon wafer surfaces. Very good surface passivation could be reached leading to a surface recombination velocity (SRV) below 10 cm/s on 1 Ω cm p‐type Si wafers. By using the passivation layer system at a solar cell's rear side and applying the laser‐fired contacts (LFC) process, pointwise local rear contacts have been formed and an energy conversion efficiency of 21·7% has been obtained on p‐type FZ substrates (0·5 Ω cm). Simulations show that the effective rear SRV is in the range of 180 cm/s for the combination of metallised and passivated areas, 120 ± 30 cm/s were calculated for the passivated areas. Rear reflectivity is comparable to thermally grown silicon dioxide (SiO₂). a‐Si rear passivation appears more stable under different bias light intensities compared to thermally grown SiO₂. Copyright © 2008 John Wiley & Sons, Ltd.     

Temperature dependence of residual stress in epitaxial GaAs/Si(100) films determined from photoreflectance spectroscopy data

In the temperature range T=10–300 K, photoreflectance spectroscopy was used to study the temperature dependence of residual stress in epitaxial n-GaAs films (1–5 μm thick, electron concentration of 10¹⁶–10¹⁷ cm⁻³) grown on Si(100) substrates. A qualitative analysis showed that the photoreflectance spectra measured in the energy region of the E ₀ transition in GaAs had two components. They consisted of the electromodulation component caused by the valence subband |3/2; ±1/2〉-conduction band transition and the low-energy excitonic component. The magnitude of stress was determined from the value of the strain-induced energy shift of the fundamental transition from the subband |3/2; ±1/2〉 with respect to the band gap of the unstressed material E ₀(T)-E ₀ ^{|3/2; ±1/2〉} (T). The increase in the energy shift E ₀-E ₀ ^{|3/2; ±1/2〉} from 22 ± 3 meV at 296 K to 29 ± 3 meV at 10 K, which was found in the experiments, gives evidence of an increase in biaxial stress with decreasing temperature. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 34, No. 1, 2000, pp. 73–80. Original Russian Text Copyright ? 2000 by Kuz’menko, Ganzha, Bochurova, Domashevskaya, Schreiber, Hildebrandt, Mo, Peiner, Schlachetzki.     

1～7GHz全单片低噪声放大器

一种性能优异的全单片宽带低噪声反馈放大器已研制成功。此两级放大器的特点是 ,性能稳定 ,频带宽 ,噪声低 ,增益高而平坦 ,可直接由 +5 V单电源供电 ,无需外加偏置电路 ,输入输出由 MIM电容隔直 ,使用方便。它由栅长为 0 .5 μm Ga As工艺制作而成 ,所有电路元器件皆集成在 3 .0 mm× 2 .0 mm的 Ga As衬底上。经测量 ,在频率 1～ 7GHz的范围内 ,放大器增益大于 2 0 d B,带内增益波动小于± 0 .75 d B,噪声系数 NF<2 .5d B,输入输出驻波 VSWR约 2 .0 ,1分贝压缩点输出功率大于 1 4d Bm。文中介绍了放大器的设计原理和工艺过程 ,并给出了测量结果。测量结果与设计符合得很好。最后值得指出的是 76mm Ga As圆片的成品率高 ,性能一致性好。     

F原子3p~4S~0-3s~4P跃迁产生的激光

用角动量理论和库仑近似法计算了F原子和Si~+离子有关跃迁几率和能级寿命。证实634.8nm激光系由F原子3p~4S_(3/2)~0-3s~4P9_(3/2)跃迁产生。     

Autodiffusion: a novel method for emitter formation in crystalline silicon thin‐film solar cells

The in situ formation of an emitter in monocrystalline silicon thin‐film solar cells by solid‐state diffusion of dopants from the growth substrate during epitaxy is demonstrated. This approach, that we denote autodiffusion, combines the epitaxy and the diffusion into one single process. Layer‐transfer with porous silicon (PSI process) is used to fabricate n‐type silicon thin‐film solar cells. The cells feature a boron emitter on the cell rear side that is formed by autodiffusion. The sheet resistance of this autodiffused emitter is 330 Ω/□. An independently confirmed conversion efficiency of (14·5 ± 0·4)% with a high short circuit current density of (33·3 ± 0·8) mA/cm² is achieved for a 2 × 2 cm² large cell with a thickness of (24 ± 1) µm. Transferred n‐type silicon thin films made from the same run as the cells show effective carrier lifetimes exceeding 13 µs. From these samples a bulk diffusion length L > 111 µm is deduced. Amorphous silicon is used to passivate the rear surface of these samples after the layer‐transfer resulting in a surface recombination velocity lower than 38 cm/s. Copyright © 2006 John Wiley & Sons, Ltd.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

ICP刻蚀在微加速度传感器制作中的应用

针对ICP刻蚀工艺进行了深入研究,探讨了气体流量、射频功率和工作室气压设定值等工艺参数对刻蚀效果的影响,最终在硅基底上获得了线宽为40μm时深刻蚀的最佳工艺参数,即采用BOSCH工艺,压力设定为6Pa,在刻蚀过程中通入流量为100cm3/min的SF6气体,持续11s,射频功率20W,源功率450W,保护过程中通入流量为75cm3/min的C4F8气体,持续10s,射频功率0W,源功率220W,得到了最佳刻蚀结果,并利用此工艺制作出了量程为±12g,灵敏度为79mV/g,精度高于±2%微机械加速度传感器。     

21≤Z≤26类氟离子精细结构能级和跃迁波长的MCDF计算

本文用相对论多组态Dirac-Fock广义平均能级模型(MCDF-EAL)计算了可能成为激光工作物质的类氟ScXIII、TiXVI、VXV、CrXVI、MnXVII和FeXVIII的2s~2p~5、2s2p~6、2s~22p~43s、2s~22p~43p组态的精细结构能级和若干3s-3p跃迁波长值。预言了一些离子的3p组态能级和3s-3p跃迁波长值。     

33≤Z≤40类氟离子精细结构能级和跃迁波长的相对论多组态Dirac-Fock计算

本文用相对论多组态Dirac-Fock广义平均能级模型计算了可能成为激光工作物质的类氟AsXXV、SeXXVI、BrXXVII、KrXXVIII、RbXXIX、SrXXX、YXXXI和ZrXXXII的2s~2p~5、2e2p~6、2s~22p~43s、2s~2p~43p组态的各30个精细结构能级和54个3s-3p跃迁波长,大部分计算值都是本文首次预言的。     

Anomalous line broading of donor transitions in high-purity InP in high magnetic fields

New lines shapes, not predicted by Stark broadening, are reported for 1s→2p (m=?1, 0) for a single hydrogenlike donor in InP. Stark-effect inhomogeneous broadening is suppressed by a magnetic field in GaAs according to both theory and experiment but the characteristic low frequency tail is enhanced by the high magnetic field for both 1s→2p (m=?1, 0) in InP.     

Ba原子6s2 1S0 - 6s6p3P1跃迁Hanle效应实验研究

Ba原子是光频标的候选者之一,对其进行有效的激光冷却与囚禁需要相关能级的寿命和跃迁几率的信息。Ba原子激发态6s6p 3P1能级在激光冷却实验中很重要,通过Hanle效应实验测量了这一能级的寿命和自发辐射率,从理论和实验上研究了探测激光有限线宽和光强对Ba原子基态6s2 1S0与激发态6s6p 3P1之间跃迁（波长791 nm）的Hanle效应的荧光信号的影响。在考虑了激光线宽和光强因素后所得到的激发态6s6p 3P1的能级寿命和自发辐射率与其他方法给出的结果很好符合。     

Silicate formation at the interface of Hf-oxide as a high-k dielectrics and Si(0 0 1) surfaces

The composition and chemical bonding of the first atoms across the interface between Si(0 0 1) and the gate dielectrics determine the quality of gate stacks. An analysis of that hidden interface is a challenge as it requires high sensitivity in both elemental and chemical state information. We used synchrotron radiation (SR) based photoelectron spectroscopy and, in particular, X-ray absorption spectroscopy in total electron yield and total fluorescence yield at the Si2p and the O1s edges to address this issue. We report on results for Hf oxide prepared by ALD and compare to Pr₂O₃/Si(0 0 1). For Hf oxide thin films we find evidence for the silicate formation at the interface as derived from the characteristic features in the X-ray absorption spectra at the Si2p and the O1s edges. Resonant photoelectron spectroscopy is used to analyze the absorption band in detail. Following the resonant profiles of initial and final states we deduce from the resonant behaviour a charge donation via a Si-induced charge transfer.     

Diffusion of chromium into epitaxial gallium arsenide

Diffusion of Cr into epitaxial GaAs in an open system in the temperature range of 750–850°C was studied. Temperature dependences of the diffusion coefficient and solubility of Cr in GaAs were determined. Temperature dependences of the diffusion coefficient and solubility of Cr are described by the Arrhenius equation with the parameters D ₀ = 1.9 × 10⁹ cm²/s and E = 4.1 ± 0.2 eV for the diffusion coefficient and N ₀ = 2.3 × 10²⁴ cm^?3 and E ₀ = 1.9 ± 0.4 eV for solubility. The effect of protective SiO₂ filmon the Cr diffusion coefficient and morphology of the GaAs surface after diffusion was studied.