几种掺杂浓度的GaAs表面Si—δ杂结构研究

本文利用了光调制光谱，原位测量了ＧａＡｓ（００１）表面Ｓｉ－δ掺杂结构样品，研究了不同要浓度对Ｓｉ－δ掺杂相关的光谱结构的影响，观察到了Ｓｉ－δ掺杂结构中，价带连续态到导带半Ｖ－形势阱中子带的跃迁，观察到该跃迁相随掺杂浓度增加先向高能移动，而后达到饱和。     

SiGe／Si量子阱结构材料的激子发光谱

在用分子束外延生长的ＳｉＧｅ／Ｓｉ多量子阱结构中，观察到激子发光光谱，从无声子参与的或ＴＯ－声子参与的激子发光峰位能量，计算了量子阱中合金的组份，并与通过Ｘ－射线衍射谱得到的结果作了比较，发现在Ｇｅ的组份比较小时，利用激子发光峰位能量确定合金组份比利用Ｘ－射线衍射谱更为方便和精确．     

几种掺杂浓度的GaAs表面Si-δ掺杂结构研究

本文利用了光调制光谱（ＰＲ），原位测量了ＧａＡｓ（００１）表面Ｓｉ－δ掺杂结构样品，研究了不同掺杂浓度对Ｓｉ－δ掺杂相关的光谱结构的影响，观察到了Ｓｉ－δ掺杂结构中，价带连续态到导带半Ｖ－形势阱中子带的跃迁，观察到该跃迁相随掺杂浓度增加先向高能移动，而后达到饱和．用简单的三角势模型，在理论上计算了面掺杂浓度２．４×１０１４ｃｍ－２时，半Ｖ－形势阱中子带的能级位置，波函数的分布及光吸收系数，与实验结果相一致．     

Cd_（1－x）Mn_xTe／CdTe多量子阱的光反射研究

本文首次报道用光调制光谱（ＰＲ）研究了Ｃｄ１－ｘＭｎｘＴｅ／ＧｄＴｅ半磁半导体多量子阱的能带结构和带间跃迁，观察到多量子阱的各子能级激子跃迁１１Ｈ．１１Ｌ，２２Ｈ，３３Ｈ等，并得到轻重空穴分裂为１８ｍｅＶ．当能带偏移Ｑｃ＝０．９０时，理论计算的子带跃迁能量与调制光谱结果符合很好．发现低温时第二子能级跃迁比第一子能级跃迁更强，并给出了初步解释，通过变温测量，测得各子能级的温度系数并与纯ＣｄＴｅ及Ｃｄ１－ｘＭａｘＴｅ混晶体材料的温度系数作了比较．     

Cd1—xMnxTe／CdTe多量子阱的光反射研究

本文首次报道用光调制光谱（ＰＲ）研究了Ｃｄ１－ｘＭｎｘＴｅ／ＣｄＴｅ半磁半导体多量子阱的能带结构和带间跃迁，观察到多量子阱的各子能级激子跃迁１１Ｈ，１１Ｌ，２２Ｈ，３３Ｈ等，并得到轻重空穴分裂为１８ｍｅＶ。当能带偏移Ｑｃ＝０．９０时，理论计算的子带跃迁能量与调制光谱结果符合很好。发现低温时第二子能级跃迁比第一子能级跃迁更强，并给出了初步解释，通过变温测量，测得各子能级的温度系数并与纯ＣｄＴｅ及Ｃｄ     

In1—xGaxAsyP1—y／InP多量子阱的光调制反射光谱

报道了组分y=0.76和0.84的晶格匹配In_(1-x)Ga_xAs_yP_(1-y)/InP多量子阱的子能带结构低温光调制反射光谱研究结果,在0.9～1.5eV光子能量范围观察到限制的电子与空穴子带间的激子跃迁,还观察到限制的电子子带与空穴连续态间的跃迁,由此比较直接地确定了价带的不连续量,得到不连续因子Q_v=0.65±0.02。     

强激光诱导NO分子的多光子光声光谱

以Nd∶YAG激光器抽运的光学参量发生/放大器为激发源,采用脉冲光声（PA）光谱技术,获得了NO分子在420.0～470.0 nm波长区间的激光诱导光声光谱,光谱由规则的振动序列组成。通过测量光声信号随激光强度的变化,确定了光声信号产生于NO分子经X^2Π（v″=0）→A^2Σ（v′=0,1）的双光子激发跃迁及X^2Π（v″=0）→E^2Σ（v′=2,3,4）,F^2Σ（v′=1,2,3）,R^2Σ（v′=0,1）的三光子激发跃迁,对应于双光子激发跃迁的光声信号比通过三光子激发跃迁产生的光声信号强,由此确定了以可见光作激发光源,采用光声技术对NO分子进行探测的最佳激发波长为452.4 nm或429.6 nm。以实验结果为基础,获得了NO分子A^2Σ,E^2Σ,F^2Σ,R^2Σ激发电子态的振动常数分别为2346 cm^-1,2342 cm^-1,2397 cm^-1,2381 cm^-1,与采用其他方法测量的结果符合得较好。     

SiGe／Si多量子阱中垂直方向红外吸收及共振色散效应

用垂直入射的中红外光束调制非掺杂SiGe/Si量子阱中光致子带间吸收，氩离子激光器作为子带间跃迁的光泵浦源在阱中产生载流子，红外调制光谱用步进式傅立叶变换光谱仪记录，实验中观察到明显的层间干涉效应与子带间跃迁有关的色散效应，理论和实验分析认为样品折射率变化造成的位相调制可以补偿吸收所造成的幅度调制。     

GaAs／AlxGa1—xAs多量子阱红外探测器的光调制光谱研究

运用光调制光谱方法测量了ＧａＡｓ／ＡｌｘＧａ１－ｘＡｓ多量子阱红外探测器材料的调制反射谱，结果表明光调制光谱可以精确确定阱宽、Ａｌ组分、子带跃迁能量和探测峰值波长等许多重要参数。结合实验结果，采用Ｋｒｏｎｉｇ－Ｐｅｎｎｙ模型对材料能带结构进行了理论计算，与实验结果相符。     

GaAs／Al_xGa_（1－x）As多量子阱红外探测器的光调制光谱研究

运用光调制光谱方法测量了ＧａＡｓ／ＡｌｘＧａ（１－ｘ）Ａｓ多量子阱红外探测器材料的调制反射谱，结果表明光调制光谱可以精确确定阱宽、Ａｌ组分、子带跃迁能量和探测峰值波长等许多重要参数，结合实验结果，采用Ｋｒｏｎｉｇ－Ｐｅｎｎｙ模型对材料能带结构进行了理论计算，与实验结果相符．     

ZnO薄膜材料的发光特性

回顾了最近几年对 Zn O薄膜材料发光特性的研究进展 ,介绍了用不同方法制备 Zn O薄膜的自发辐射和受激辐射发光特性。     

还原气氛对Sr1.94－xBaxMgSi2O7:Eu2+0.01，Dy3+0.05长余辉材料发光性能的影响

用高温固相反应法,分别在H₂和CO还原气氛 中制备了Sr1.94－xBaxMgSi ₂O₇:Eu²⁺0.01,Dy³⁺0.05长 余辉材料;研究了不同还原气氛对该系列荧光粉发光及余辉性能的影响。研究结果表明,随 着Ba²⁺浓度的增 加,荧光粉的晶体结构发生了改变,从而导致发射光谱和余辉光谱的峰位也发生了变化;CO 还原气氛下所制备荧光 粉的纯度要高于H₂还原气氛下制备的样品,CO还原气氛下所制备荧光粉的余辉的初始亮 度和衰减都明显优于H₂还原条件下所制备的样品,说明CO还原条件下更容易形成具有合 适浓度和深度陷阱的纯相荧光粉,有助于提高样品的余辉性能。     

激发波长和电化学腐蚀对注碳外延硅荧光特性的影响

电化学腐蚀是蓝光发射的前提,但不同的电化学腐蚀条件对发光强度和峰位影响极大,随着电化学腐蚀条件的加强,蓝光峰将被红光峰代替。激发光波长亦可影响蓝光发射,如260nm的激发光将引起在360nm光激发下所获得的431nm蓝光峰的蓝移。     

有机-无机复合薄膜电致发光器件中势垒对光电性能的影响

利用无机非晶SiO2与有机聚合物PPV复合制备了异质结器件,研究了不同层之间由于能级匹配而产生的势垒对整个器件的光电性能的影响。对于单层有机器件ITO/PPV/Al及双层有机无机复合器件ITO/PPV/SiO2/Al,空穴的注入取决于ITO/PPV界面的势垒,空穴是多数载流子,发光强度主要取决于电子的注入。单层器件电子的注入能力与PPV/Al界面的势垒有关;双层器件由于引进SiO2层,提高了电子的注入能力,其发光强度和发光效率较单层器件都有改善。对于3层有机-无机复合器件ITO/SiO2/PPV/SiO2/Al,在两个方向上电子注入的势垒不同,电子的注入能力有所差别,交流激发时,当Al电极为负(ITO为正)时,器件的最大瞬时发光强度是当ITO电极为负(Al为正)时最大瞬时发光强度的1.3倍。     

增强硅中掺铒发光强度的途径研究

硅在微电子学领域有着极其广泛的应用,但它是一种间接能隙半导体,发光器件领域是它的缺项。利用在硅中掺入铒发光中心,研制出一种新的发光二极管（Si：ErLED）,它的发光波长为1.54μm,恰好满足石英光纤通信的要求。对掺铒硅的电学特性、材料性能、发光机理等进行了总结,发现制约掺铒硅实用化的一些问题,在此基础上得出提高其发光效率的途径,并介绍了掺铒硅器件的行为和未来展望。     

Effects of Zn-vapor heat treatments on the edge emission and deep-center luminescence of ZnTe

Using cathodoluminescence measurements at 80–300K, we have investigated the effects of Zn-vapor heat treatments on the injection level dependence, frequency response, and temperature dependence of the edge emission and the extrinsic deepcenter luminescence of vapor-phase-grown ZnTe. The results are compared to those from the same material in its as-grown condition. Zn-vapor heat treatments greatly enhance the 1.8 eV deep-center band and make it the dominant spectral feature at all temperatures investigated. The resulting band shows little change in shape or energy with injection level, and the temperature dependence of the band does not suggest thermal exchange between a participating energy level and a band edge. While the energy of the 1.8 eV band does decrease with increasing temperature, it does not match the variation of the band gap with temperature. It is found that the 1.8 eV band broadens with increasing temperature in a way satisfactorily explained by configurationcoordinate modeling. The kinetics of the 1.8 eV band show complex detail, both at 80K and 300K, but microsecond-magnitude exponential components are dominant. In contrast, the kinetics of the edge emission are much faster. However, despite the difference in kinetics, the intensities of the 1.8 eV band and the edge emission at 80K scale closely with each other over a wide range of injection levels. This remarkable result indicates that the edge emission and deep-center luminescence processes do not involve independent competition for injected carriers in Zn-fired ZnTe.     

Temperature,injection level,and frequency dependences of some extrinsic luminescence bands in ZnTe

Using cathodoluminescence measurements between 80 and 300 K, we have investigated the temperature, injection level, and frequency dependences of three extrinsic luminescence bands in nominally undoped ZnTe. At 80 K, our material shows strong edge emission and broad extrinsic bands near 1.59 eV and 2.08 eV. The peak position and band shape are independent of injection level for both these extrinsic bands. 80 K measurements of frequency response from 50 Hz to 50 MHz show that the 2.08 eV band has an exponential time decay with a time constant of 0.045 μsec. The 1.59 eV band shows a more complex frequency dependence which indicates that one component of the response has a time constant of 1.85 μsec. At temperatures above 80 K the 2.08 eV band quenches with an activation energy of 0.22 eV which indicates that the transition originates near a band edge. In contrast, the 1.59 eV band does not quench with a well-defined activation energy. The peak of the 2.08 eV band follows the temperature dependence of the edge emission energy, whereas the peak of the 1.59 eV band shows the opposite behavior. From the 80 K measurements, we conclude that the 2.08 eV band results from a conduction-band-to-acceptor transition, and that the 1.59 eV band results from an intracenter transition between localized levels of a compact complex. Above 160 K, a third extrinsic band begins to appear near 1.80 eV. This band becanes increasingly prominent with increasing temperature. The frequency dependence of the 1.80 eV band at 166 K indicates an exponential time decay with a time constant of 0.37 μsec. However, the frequency dependence changes with temperature and a faster component appears in the response at 300 K. We conclude that 1.80 eV band near 160 K results primarily from an intracenter transition in a compact complex, and that there is a contribution from free-to-bound transitions at 300 K.     

Cathodoluminescence studies of the 1.4 eV bands in vapor-phape-grown CdTe

Vapor-phase-grown CdTe is interesting in that it represents an alternate growth technology for CdTe and in addition provides an alternate setting in which to observe the poorly-understood 1.4 eV luminescence that has received much attention in liquid-phase-grown material. In this paper we present the first cathodoluminescence measurements in vapor-phase-grown CdTe. We describe the injection level dependence, temperature dependence, and frequency response of the luminescence of vapor-phase-grown CdTe and compare the results to those reported previously on liquid-phase-grown CdTe.     

Multistimuli‐Responsive Display Materials to Encrypt Differentiated Information in Bright and Dark Fields

Visually readable codes play a crucial role in anticounterfeiting measures. However, current coding approaches do not enable time‐dependent codes to be visually read, adjusted, and differentiated in bright and dark fields. Here, using a combined strategy of piezoelectric lattice selection, oxygen vacancy engineering, and activator doping, a lanthanide ion‐doped titanate is developed that integrates mechano‐, thermo‐, and photo‐responsive color change (>18 h for bright field), persistent luminescence (>6 h for dark field), and stimulus‐triggered multimodal luminescence. The feasibility of optical encoding, visual displaying, and stimulus‐responsive encrypting of time‐dependent, dual‐field information by using the developed material is demonstrated. In particular, the differentiated display of dual‐field modes is achieved by combining mechanostimulated abolition of only the persistent luminescence and thermo‐ and photostimulated reversal of both the color change and persistent luminescence. The results provide new insights for designing advanced materials and encryption technologies for photonic displays, information security, and intelligent anticounterfeiting.     

直流场作用下蒜的超弱发光与延迟发光

本文用自制的测试系统（单光子计数器,其单光子暗计数为０．１ｓ＾－１·ｃｍ＾－２）,测得白光照射下蒜的延迟发光为双曲线,符合Ｆ．Ａ．Ｐｏｐｐ的相干理论;当用直流场作用蒜瓣时测得超弱发光呈振荡上升,表明直流场使生命内有序过程增加。