K0．3MoO3电子辐照下有序一无序转变及恢复

准一维K0．3MoO3蓝青铜中的电荷密度波(CDW)失稳一直是凝聚态物理研究的热点之一。在180K温度附近K0．3MoO3发生晶格畸变伴随着电荷发生空间周期性调制，形成所谓的CDW。当调制波矢量q=2Kr时，布里渊区将与费米面套叠而打开一个Peierls能隙，导致体系从导体向半导体或绝     

电子辐照快速恢复二极管

电子辐照快速恢复二极管莫长涛李钢黑龙江商学院基础部（哈尔滨１５００７６）本试验为ＺＫ５０Ａ快速恢复二极管。芯片厚３２０μｍ，ｎ型衬底电阻率３０～５０Ω·ｃｍ。将二极管芯片置于ＪＪ１．２型电子静电加速器扫描盒下，在大气室温环境下用电子束照射。为试验辐照...     

电子辐照减小大电流快速恢复二极管的反向恢复时间

报告了用电子辐照方法减小快速恢复二极管反向恢复时间的实验结果。     

电子辐照减小大电流快速恢复二极管的反向恢复时间

报告了用电子辐照方法减小快速恢复二极管反向恢复时间的实验结果。     

自然氧化和电子辐照对多孔硅结构有序度的影响

多孔硅在空气中自然氧化形成Si—O—Si键,引起晶格畸变,导致有序度下降,氧化层用HF去除,有序度可恢复。大束流电子束辐照直接引起晶粒无序化,其有序度不能在HF浸泡中恢复。     

MoO3纳米带在外场作用下的相变

本文研究了电子束辐照和加热条件下正交相MoO3的相变.利用透射电子显微学研究表明:(1)电子束辐照使MoO3相变生成具有面心立方结构的MoO,两相之间取向关系为[010]MoO3//[010]MoO,(200)MoO3//(200)MoO;(2)MoO3在873 K时相变生成单斜相的MoO2,在相变产物中首次发现了具有(011)孪晶的MoO2纳米颗粒.研究结果使之对MoO3在不同环境下的相变有了更深入的了解.     

MoO3纳米线有序阵列在微流芯片中的Cd2+离子传感特性研究

采用水热合成技术生长MoO_3纳米线,利用介电泳技术在微电极上组装MoO_3纳米线阵列,研究了纳米线阵列对水中Cd~(2+)离子浓度的传感特性。结果表明,水热法所得纳米线为正交相MoO_3结构,长度可达20μm。在介电泳力作用下,纳米线可在微电极的间隙取向排列,构成沿水平方向平行排列的纳米线阵列。将所得纳米线阵列与微流控芯片相集成,可获得用于液体离子浓度探测的微型传感器件。器件在室温下,对水溶液中浓度为1～50μmol/L的Cd~(2+)离子表现出快速灵敏的线性响应特性。其中,当Cd~(2+)离子溶液浓度为50μmol/L时,传感器的电阻开关比约为4.8,响应时间约为114 s。随着Cd~(2+)离子浓度逐渐降低,传感器的电流开关比线性下降,响应时间逐渐缩短。根据傅里叶变换红外光谱结果,MoO_3纳米线阵列这种快速、灵敏的Cd~(2+)离子敏感特性主要来自水热反应后其表面携带的羟基官能团所致。     

电子辐照下的SiC少子寿命退化模型

从理论上对电子辐照在4H-SiC中引入的缺陷数量和各种缺陷能级进行了分析.结果表明,EH6和EH7缺陷能级在4H-SiC中起着有效复合中心的作用.采用SRH模型来估计电子辐照下4H-SiC的少子寿命,并给出了电子辐照下4H-SiC少子寿命损伤系数的模型.结合具体的测量条件,证明了这个模型是合理的.辐照电子对Si、GaAs和4H-SiC产生的不同影响展示了在高空、高辐照条件下 SiC存在着优势.     

电子辐照下的SiC少子寿命退化模型

从理论上对电子辐照在４Ｈ－ＳｉＣ中引入的缺陷数量和各种缺陷能级进行了分析．结果表明,ＥＨ６和ＥＨ７缺陷能级在４Ｈ－ＳｉＣ中起着有效复合中心的作用．采用ＳＲＨ模型来估计电子辐照下４Ｈ－ＳｉＣ的少子寿命,并给出了电子辐照下４Ｈ－ＳｉＣ少子寿命损伤系数的模型．结合具体的测量条件,证明了这个模型是合理的．辐照电子对Ｓｉ、ＧａＡｓ和４Ｈ－ＳｉＣ产生的不同影响展示了在高空、高辐照条件下ＳｉＣ存在着优势     

制备工艺对0.7CaTiO3-0.3NdAlO3材料的影响

用固相反应和熔盐法制备工艺合成了0.7CaTiO3-0.3NdAlO3(CTNA)粉体,研究了制备工艺对CT-NA陶瓷的合成过程和微波介电性能的影响。结果表明,相比于固相反应的长时间合成,熔盐法中,混合粉料在1 200℃2、h下即可合成CTNA单相,样品在1 375℃下可烧结致密,获得的样品具有与固相反应相当的微波介电性能,即介电常数rε=43;品质因数与频率的乘积Q×f=35 736 GHz;频率温度系数τf=1.32×10-6/℃。     

Improving the reverse recovery of power mosfet integral diodes by electron irradiation

This paper demonstrates that controlled electron irradiation of silicon power MOSFET devices can be used significantly improve the reverse recovery characteristics of their integral reverse conducting diodes without adversely affecting the MOSFET characteristics. By using 3 MeV electron irradiation at room temperature it was found that the reverse recovery charge in the integral diode could be continuously reduced in a well controlled manner from over 500 nC to less than 100 nC without any significant increase in the forward voltage drop of the integral diode under typical operating peak currents. The reverse recovery time was also observed to decrease from 3 microseconds to less than 200 nsec when the radiation dose was increased from 0 to 16 Megarads. The damage produced in gate oxide of the MOSFET due to the electron radiation damage was found to cause an undersirable decrease in the gate threshold voltage. This resulted in excessive channel leakage current flow in the MOSFET at zero gate bias. It was found that this channel leakage current was substantially reduced by annealling the devices at 140°C without influencing the integral diode reverse recovery speed. Thus, the electron irradiation technique was found to be effective in controlling the integral diode reverse recovery characteristics without any degradation of the power MOSFET characteristics.     

X射线辐照下材料电子发射特性的模拟

稳态 X 射线管是一种重要的 X 射线辐照模拟装置,在辐照效应等研究领域有重要应用。采用蒙特卡罗模拟方法计算了 50 kV,150 kV 和 225 kV 管电压下的 X 射线能谱,并对 X 射线辐照下电子发射进行了模拟;研究了准直孔直径分别为 2 mm,4 mm 和 6 mm 条件下 X 射线的焦斑分布和电子发射弥散情况,以及不同能谱的 X 射线轰击到聚乙烯、聚酰亚胺、Si、SiO₂、Cu、Ta 和 W等样品上产生的电子发射能谱和电流强度等特性,为 X 射线辐照下材料电子发射特性的实验研究和设计提供一定的理论基础和指导。     

Defect-engineering in SiC by ion implantation and electron irradiation

Three examples are given, which show that ion implantation and electron irradiation can drastically modify the electrical properties of SiC and SiC-based MOS capacitors. (1) It is demonstrated that sulphur ions (S⁺) implanted into 6H-SiC act as double donors with ground states ranging from 310 to 635 meV below the conduction bandedge. (2) Co-implantation of nitrogen (N⁺) - and silicon (Si⁺) - ions into 4H-SiC leads to a strong deactivation of N donors. Additional experiments with electron (e⁻)-irradiated 4H-SiC samples (E(e⁻) = 200 keV) support the idea that this deactivation is due to the formation of an electrically neutral (N_x-V_C, y)-complex. (3) Implantation of a surface-near Gaussian profile into n-type 4H-SiC followed by a standard oxidation process leads to a strong reduction of the density of interface traps D_it close to the conduction bandedge in n-type 4H-SiC/SiO₂ MOS capacitors.     

具有高效空穴注入的高电子传输层的白光电致发光器件

以M003或m-MTDATA作为空穴注入层,Alqa或Bphen作为电子传输层组合了4组白色有机电致发光器件.发光层为9,10-bis(2-naphthyl)-2-t-butylanthracene(TBADN)掺杂3%的P-bis(P-N,N-diphenyl-aminos-tyryl)benzene(DSA-ph)作为蓝色掺杂剂和0.05%的4-(dicyanomethylene)-2-t-bul:yl-6-(1,1,7,7,-tetramethyl-julolidy-9-enyl)-4H-pyran(DCJTB)作为红色掺杂剂.研究表明基于M003//Bphen结构的器件大大降低了驱动电压,改善了功率效率,在电流密度为20 mA/cm2时,其值分别为5.43 V和4.54 lm/W.与基于m-MTDA-TA//Alq3结构的器件相比,驱动电压降低了40%,功率效率提高57%.     

LaLu0.7Er0.3O3纳米多晶的制备、结构和光谱特性

采用共沉淀法制备了LaLu0.7Er0.3O3的纳米多晶粉体.对它进行了X射线粉末衍射测试,根据衍射峰宽估算了粉体颗粒的尺寸,同时利用Rietveld全谱拟合方法确定了它的结构.在室温下,测试研究了它的吸收和光致发光谱.并利用380 nm光激发,测试了1.5 μm红外(4I13/2→4I15/2)光的荧光衰减情况,给出了相应荧光寿命.结果表明, LaLu1-xErxO3是一种值得深入研究并具有潜在应用价值的红外激光材料.     

A study of electron transition in the energy gap of SI-GaAs with photoconductivity spectra and under α-particle irradiation

The aim of the present work is to study the density of electron transitions inside the energy gap of SI-GaAs at various temperatures and under α-particle irradiation at 300 K. The photocurrent as a function of photon energy from 1.35 to 1.80 eV, for each temperature, was measured in the temperature range from 180 to 300 K. From the spectra analysis for each temperature, three peaks were found. The energy that corresponds to the peaks as a function of temperature was plotted. The temperature and the irradiation strongly affect the value of the peaks, which is related to the number of transitions of the electrons inside the energy gap. As the temperature decreases, the peaks follow the same change. After irradiation, the values of the peaks decrease for all temperatures and this decrease is more intense for the P3 peak.     

Carbon ions irradiation induced modifications in structural and electrical resistivity characteristics of ZrN thin films

Zirconium nitride (ZrN) thin films are irradiated with 800 keV energetic carbon (C) ions in a 5UDH-Pelletron accelerator and the ions irradiation induced effects are investigated. The films are irradiated at various C ions fluences, ranging from 10¹³ to 10¹⁵ ions/cm². The scanning electron microscopy study of the films indicates the development of zirconium (Zr) nanoparticles at ions irradiated region. X-ray diffraction (XRD) patterns of C ions irradiated films also show the formation of (100) and (002) oriented nanocrystalline metallic Zr phases. The irradiated films spectra depict a shift in ZrN peaks towards higher 2θ values, exhibiting that C ions bombardment induces compressive stress in the irradiated films. The appearance of C related peaks in Fourier transform infrared (FTIR) spectra confirms the incorporation of C atoms into ZrN film. Compressive stress has been calculated from the IR peak shift which indicates that higher ion dose (≥5×10¹⁴ ions/cm²) produce lower compressive stress relative to the lower ions fluences. Effect of ion dose on the film resistivity is also reported.     

调整VO2薄膜相变特性和TCR的制备及辐照方法

采用不同的真空还原时间、真空退火温度和衬底制备出了VO2薄膜,并对制备出的薄膜进行电子辐照.通过测试辐照前后的VO2薄膜相变电学性能及低温半导体相电阻温度系数(TCR),表明不同的制备工艺和不同注量的电子辐照可明显改变VO2薄膜相变过程中电学性能,提高薄膜的电阻温度系数.对影响VO2热致相变薄膜电学性能及电阻温度系数的因素进行了讨论.     

离线热处理和原位电子辐照下羟基硫酸镍纳米带结构演变的TEM研究

利用透射电子显微术,主要包括亮场像形貌观察、选区电子衍射结合运动学模拟计算和高分辨电子显微像,对水热法制备的结晶良好的Nj(SO4)0.3(OH)1.4纳米带结构和生长形态进行了表征,并结合利用在不同温度的离线热处理及原位电子辐照,对从结晶良好的Nj(SO4)0.3(OH)1.4纳米带到疏松多孔的NiO纳米带,最后到NiO纳米颗粒的结构演变进行了系统研究,得到了Nj(SO4)0.3(OH)1.4和NiO的取向关系,揭示了这一系列过程的结构演变并给出了Nj(SO4)0.3(OH)1.4的初步结构模型.     

Switching speed enhancement in insulated gate transistors by electron irradiation

High-speed switching in insulated gate transistors (IGT's) has been achieved by using electron irradiation. This technique allows excellent control over the switching speed with the ability to reduce the gate turn-off time from over 20 µs to under 200 ns. This increase in speed is accompanied by an increase in the forward voltage drop during current conduction. This necessitates performing a trade-off between switching and conduction losses. Despite the increase in the forward drop, the IGT's exhibit superior characteristics in comparison with power MOSFET's and bipolar transistors up to switching frequencies of 100 kHz.