用Columnar模型对电子空穴对复合逃逸产额的模拟计算

用一种比较简单的Jaffe近似方法计算了质子在SiO2中的电子空穴对的逃逸率,讨论了辐照偏置、电场、质子入射角度、质子能量等对逃逸产额的影响.得到了电子空穴对复合逃逸率与质子能量、电场成正比的结果.计算结果与实验结果的比较,说明了Jaffe近似方法可以比较正确地描述质子在二氧化硅中的总剂量效应.     

潮解对CsI光阴极量子产额的影响

CsI光阴极在空气中易潮解是导致实际使用时量子产额降低的重要原因。使用扫描探针显微镜观察CsI光阴极在潮解前后的表面形貌变化,发现CsI晶粒在潮解后的直径与高度变大,且CsI薄膜的覆盖率降低。对CsI光阴极潮解后的表面形貌建模,通过蒙特卡罗模拟来研究CsI光阴极的量子产额在潮解前后的变化。模拟结果显示,CsI晶粒的直径和高度变大会导致CsI光阴极的量子产额下降,并且表面形貌变化越大量子产额下降越多。因此,可以认为潮解造成CsI光阴极量子产额下降的重要原因之一是CsI光阴极表面形貌的变化。     

基于异构观测链的容器逃逸检测方法

针对现有容器逃逸检测技术漏报率较高的问题,提出一种异构观测的实时检测方法。首先对利用内核漏洞的容器逃逸行为建模,选取进程的关键属性作为观测点,提出以“权限提升”为检测标准的异构观测方法;然后利用内核模块实时捕获进程的属性信息,构建进程起源图,并通过容器内外进程边界识别技术缩小起源图规模;最后基于进程属性信息构建异构观测链,实现原型系统HOC-Detector。实验结果表明,HOC-Detector可以成功检测测试数据集中利用内核漏洞的容器逃逸,并且运行时增加的总体开销低于0.8%。     

HBT空间电荷区复合电流的解析模型

建立了异质结双极晶体管ＥＢ结空间电荷区复合电流的解析模型,基于该模型计算出了不同基区掺杂浓度下空间电荷区的复合率,获得了空间电荷区复合电流随机加电压的变化关系。     

HBT空间电荷区复合电流的解析模型

建立了异质结双极晶体管ＥＢ结空间电荷区复合电流的解析模型,基于该模型计算出了不同基区掺杂浓度下空间电荷区的复合率,获得了空间电荷区复合电流随外加电压的变化关系。     

PS∶NPB复合空穴传输层的有机电致发光特性

制备了结构为indium-tin-oxide(ITO)/polystyrene(PS):N, N'-bis-(3-Naphthyl)-N, N'-biphenyl-(1,1'-biphenyl)-4,4'-diamine(NPB)/tris-(8-hydroxyquinoline)-aluminum(Alq3)/Mg:Ag的绿光双层有机电致发光器件(OLED).空穴传输层采用复合结构,为有机小分子空穴传输材料NPB与聚合物母体材料聚苯乙烯(PS)的掺杂体系,并利用旋涂工艺简化了薄膜制备.通过调节该体系的组分,制备出具有不同PS:NPB浓度比的OLED器件,并对器件的电致发光特性进行了表征.研究发现,不同的NPB掺杂浓度对复合空穴传输层以及器件的光电特性具有显著影响.当 PS和NPB的组分浓度比为1时,可以最大限度地优化该器件的性能.该项研究有助于OLED器件复合功能层的构建以及工艺方法的改进.     

PS:NPB复合空穴传输层的有机电致发光特性

制备了结构为indium-tin-oxide(ITO)/polystyrene(PS):N, N'-bis-(3-Naphthyl)-N, N'-biphenyl-(1,1'-biphenyl)-4,4'-diamine(NPB)/tris-(8-hydroxyquinoline)-aluminum(Alq3)/Mg:Ag的绿光双层有机电致发光器件(OLED).空穴传输层采用复合结构,为有机小分子空穴传输材料NPB与聚合物母体材料聚苯乙烯(PS)的掺杂体系,并利用旋涂工艺简化了薄膜制备.通过调节该体系的组分,制备出具有不同PS:NPB浓度比的OLED器件,并对器件的电致发光特性进行了表征.研究发现,不同的NPB掺杂浓度对复合空穴传输层以及器件的光电特性具有显著影响.当 PS和NPB的组分浓度比为1时,可以最大限度地优化该器件的性能.该项研究有助于OLED器件复合功能层的构建以及工艺方法的改进.     

原子和分子结构对电子阻止本领Se(E)的Z振荡的影响

本文在Firsov理论基础上,引入Slater波函数等概念,解释了原子结构对Se(E)的Z振荡的影响。它不仅能解释常规能量范围内(101000keV)的轻元素靶和重元素靶的Z振荡行为,而且能解释更高的能量范围内(10100MeV)Z振荡行为。本文引用了分子轨道法理论来处理分子靶问题,导出了分子结构对Se(E)的Z振荡影响的方程式,使能处理相当宽的能量范围内的分子靶的Se(E)的Z振荡问题。应用本文方法所得结果与Z1C和Li+Z2靶的Z1(或Z2)振荡的实验结果进行了比较,同时还与在较高能量范围的S+Na和F+Ag系统的实验结果作了比较,都得到了满意的结果,说明本文提出的方法是令人满意的。     

PVK:NPB复合空穴传输层对有机电致发光器件的影响

采用poly(N-vinylearbazole)(PVK):N,N'-bis-(1-naphthyl)-N,N'-bipheny-1,1'-biphenyl-4,4'-diamine(NPB)掺杂体系作为复合空穴传输层,通过调节该体系的组分,制备了结构为indium-tin oxide(ITO)/PVK:NPB/8-hydroxyquinoline aluminum(Alq3)/Mg:Ag的双层有机电致发光器件(OLED),研究了具有不同掺杂质量比的OLED器件的电致发光特性,并对掺杂薄膜的表面形貌进行了表征.结果表明,将NPB掺杂到PVK中会提高空穴传输能力,改善器件的发光亮度和效率,并调节载流子复合区域的位置,光谱谱峰从509 nm移动到530 mm;但随着NPB质量比例提高,掺杂薄膜表面的平均粗糙度由3 nm上升为10 mm,电流密度和亮度先升高后降低.当PVK和NPB的掺杂质量比为l:3时,器件具有最优性能,发光亮度达到7852 cd/m2,功率效率为1.75 lm/W.     

汉语连续语音识别中不同基元声学模型的复合

该文研究由不同声学基元训练的声学模型的复合。在汉语连续语音识别中,流行的基元包括上下文相关的声韵母基元和音素基元。实验发现,有些汉语音节在声韵母模型下有更高的识别率,有些音节在音素模型下有更高的识别率。该文提出一种复合这两种声学模型的方法,一方面在识别过程中同时使用两种模型,另一方面在识别过程中避开造成低识别率的模型。实验表明,采用本文的方法后,音节错误率比音素模型和声韵母模型分别下降了9.60%和6.10%。     

Modeling of Recombination in HgCdTe

Minority carrier recombination lifetime calculations for narrow-gap semiconductors are of direct practical interest in establishing whether a material’s recombination is extrinsically or intrinsically limited, and therefore in guiding research and development programs regarding material quality improvements. We describe efforts to obtain accurate electronic band structures of HgCdTe alloy-based materials with infrared energy gaps and employ them to evaluate Auger recombination lifetimes. We use a 14-band k · p formalism to compute and optimize electronic band structures, and use the obtained electronic energies and matrix elements directly in the numerical evaluation of Auger and radiative lifetimes.     

用激射延迟法研究DH激光器的复合性质

利用激射延迟方法,对GaA_3-Al_(0.3)Ga_(0.7)A_3DH激光器的复合机制进行了分析和测量.得出了只有同时考虑双分子过程辐射复合和非辐射复合两种复合机理,才能对DH激光器的激射延迟性质进行较全面研究的结论.并由此可提供一种测定辐射复合系数和少数载流子寿命的方法.     

Effect of phosphorus diffusion to the recombination at the Si–SiO2 interface

Measurements of the excess carrier lifetime of diffused and undiffused, thermally oxidized silicon samples are used to show that the presence of a phosphorus diffusion results in a modification of the interface defect properties, resulting in significantly higher surface recombination velocity compared to undiffused samples. In addition, for undiffused samples, positive and negative charges are demonstrated to be equally effective at passivating the silicon surface. Both results hold for (100) and (111) oriented samples, as well as for samples subjected to various post‐oxidation treatments. The results may have practical implications particularly for the design of rear contacted solar cells. Copyright © 2008 John Wiley & Sons, Ltd.     

双层异质结器件载流子复合位置的研究

载流子的复合是有机电致发光过程的一个重要环节,它直接影响着器件的效率,稳定性,寿命等性能。以双层器件ITO／N,N＇-Diphenyl-N,N＇-bis（1-naphthyl）-（1,1＇-biphenyl）-4,4＇-diamine（NPB）／tri-（8-hydroxy-quinoline）-aluminum（Alq3）／Mg：Ag为基础,以红光掺杂剂4-（dicyanomethylene）-2-t-butyl-6-（1,1,7,7-tetramethyljulolidyl-9-enyl）-4H-pyran（DCJTB）为探针,通过改变在Alq3层中掺杂层的厚度,研究了双层异质结器件中载流子的复合位置。结果表明,对于双层器件NPB／Alq3,载流子的复合及激子的辐射衰减位于界面处的Alq3层0～10nm范围内。     

有机电致发光器件中复合发光的电场和温度关系

通过分析有机电致发光器件中载流子注入、输运、激子的解离与复合过程，提出了激子解离与复合的理论模型。基于电流连续性方程和Poisson方程，给出了激子复合几率、电流密度及复合效率表达式。研究了外加电压和温度对器件中激子的复合几率及在各种接触条件下外加电压对器件电流和复合效率的影响。结果表明：(1)在一个较宽的注入势垒范围内，复合几率随电场和温度的升高而降低；(2)固定阴极势垒，而阳极势垒由小变大时，器件电流由接触限制向空间电荷限制转变；(3)复合效率随外加电压升高先增加，当电压达一临界值时而陡降，并存在一个最佳的注入势垒值。其计算值与所报道的实验结果相符合。     

Ge,Al共掺SiO2薄膜的发光性能研究

用射频磁控溅射法制备Ge,Al共掺SiO2复合薄膜并以不同温度进行退火,得到具有特定光致发光性质的复合材料。经600℃退火的薄膜样品在260 nm谱线激发下,主要有398和494 nm发光峰。通过对样品的X射线衍射谱和X射线光电子能谱的测试,确定了薄膜的结构特征,同时对观察到的光致发光从理论上做了重点分析,认为双重配位的Si孤对中心和GeO色心中的三重激发态到基态(T1→S0)之间的辐射跃迁分别是产生414和398 nm发光峰的主要原因。实验结果表明,Al的掺入可能在GeO2晶粒中引入了新缺陷能级,从而产生494 nm这一特殊的发光带,同时Al的掺入也提高了398 nm发光峰的发光效率。     

ZrO2/SiO2双层膜膜间渗透行为初步研究

用溶胶-凝胶技术,采用提拉镀膜法在K9玻璃基片上镀制了ZrO2/SiO2双层膜和SiO2/ZrO2双层膜,研究了这两种膜层之间的渗透问题。用X射线光电子能谱仪(XPS)测量了薄膜的成分随深度方向的变化,用反射式椭偏仪对X射线光电子能谱仪测得的实验结果进行模拟与验证。结果表明,用X射线光电子能谱仪测得的实验结果建立的椭偏模型,模拟出来的椭偏曲线和用椭偏仪测量出来的椭偏曲线十分吻合;对于ZrO2/SiO2双层薄膜,膜层间的渗透情况不是很严重,在薄膜界面处薄膜的成分比变化非常明显,到达一定深度后薄膜的成分不再随深度的变化而变化;SiO2/ZrO2双层膜膜层界面间的渗透十分严重,渗透层的深度比较大,底层几乎发生了完全渗透。     

Relationship of Band-Edge Luminescence to Recombination Lifetime in Silicon Wafers

In recent years, intrinsic luminescence has been used as a method to characterize the recombination lifetime of crystalline silicon. The assumption is that the steady-state intrinsic photoluminescence at 1.09 eV (1.134 μm) can be related to the recombination lifetime. In this work, we measured the band-edge photoluminescence (PL) intensities of a number of single-crystal wafers. The resistivity in the wafer set ranges from 1 to 11,000 ohm-cm under constant excitation intensity. We then measured the PL spectra and recombination lifetimes of these wafer sets under a variety of conditions. The lifetime was measured using resonant-coupled photoconductive decay (RCPCD) in both air ambient and an iodine/methanol solution. The same procedure was used for the PL spectra. Plots of the measured lifetime versus the PL intensity showed weak correlation between the two quantities in air ambient. However, there is a positive relationship between the near-bandgap PL intensity and the recombination lifetime for passivated surfaces. Some fundamental physical reasons will be used to explain these results.     

Correlating Emissive Non‐Geminate Charge Recombination with Photocurrent Generation Efficiency in Polymer/Perylene Diimide Organic Photovoltaic Blend Films

Evidence for a correlation between the dynamics of emissive non‐geminate charge recombination within organic photovoltaic (OPV) blend films and the photocurrent generation efficiency of the corresponding blend‐based solar cells is presented. Two model OPV systems that consist of binary blends of electron acceptor N′‐bis(1‐ethylpropyl)‐3,4,9,10‐perylene tetracarboxy diimide (PDI) with either poly(9,9‐dioctylfluorene‐co‐benzothiadiazole) (F8BT) or poly(9,9‐dioctylindenofluorene‐co‐benzothiadiazole) (PIF8BT) as electron donor are studied. For the F8BT:PDI and PIF8BT:PDI devices photocurrent generation efficiency is shown to be related to the PDI crystallinity. In contrast to the F8BT:PDI system, thermal annealing of the PIF8BT:PDI layer at 90 °C has a positive impact on the photocurrent generation efficiency and yields a corresponding increase in PL quenching. The devices of both blends have a strongly reduced photocurrent on higher temperature annealing at 120 °C. Delayed luminescence spectroscopy suggests that the improved efficiency of photocurrent generation for the 90 °C annealed PIF8BT:PDI layer is a result of optimized transport of the photogenerated charge‐carriers as well as of enhanced PL quenching due to the maintenance of optimized polymer/PDI interfaces. The studies propose that charge transport in the blend films can be indirectly monitored from the recombination dynamics of free carriers that cause the delayed luminescence. For the F8BT:PDI and PIF8BT:PDI blend films these dynamics are best described by a power‐law decay function and are found to be temperature dependent.