外加静电场下激光诱导等离子体特性的实验研究

在外加静电场下，准分子激光诱导等离子体中Ｍｇ原子５５２．８４、５１６．７３、４７０．３０ｎｍ三条发射谱线展宽的时间分辨特性的实验研究，实验测定结果表明，外加静电场导致了原子发射谱线展宽超过Ｓｔａｒｋ展宽，这种额外展宽的大小在０．１ｎｍ左右，其中４７０．３ｎｍ谱线的加宽和线移最大，采用量子理论计算表明这种额外展宽是由于在外电场中作用下作定向运动的电子与激发态原子碰撞所致。     

Ca0.9Sr0.1S:Bi3+,Tm3+荧光材料的光学性质

Ｃａ０．９Ｓｒ０．１Ｓ：Ｂｉ＾３＋,Ｔｍ＾３＋是一种复合掺杂复合基质荧光材料。在此给出了４４０ｎｍ和５２０ｎｍ发射的激发谱,２５０ｎｍ到３５０ｎｍ的激发的发射谱,以及４００ｎｍ到５２０ｎｍ的荧光衰减谱。紫外光区域的激发谱表明,Ｃａ０．９Ｓｒ０．１Ｓ：Ｂｉ＾３＋,Ｔｍ＾３＋有两个主要的能量传递体系,３２５ｎｍ的复合掺杂中心Ｔｍ＾３＋的ＣＴ跃迁激发体系,和Ｂｉ＾３＋的自身激发体系。紫外激发的荧光发射谱     

三乙基铝快速反应光谱研究

对高温激波管中三乙基铝的快速反应进行了高分辨和低分辨光谱研究，结果表明：其光谱由线性、带状和连续谱组成，范围从３５０ｎｍ到７３０ｎｍ，观测到了ＡｌＯ、ＣＨ、Ｃ２、ＣＯ等反应产物的发射谱带。文中还给出了三乙基铝的快速反应激发温度     

氧含量对a-SiOxNy薄膜荧光特性的影响

采用ＰＥＣＶＤ方法制备了ａ－ＳｉＯｘＮｙ薄膜,观察到强荧光发射现象,荧光光谱由波段范围为２６０～３５０ｎｍ和５００～７００ｎｍ的宽谱带和位置分别为３６５、３７５、３８０、７３５和７４５ｎｍ的荧光发射峰组成。改变沉积过程中氢分压研究了氧含量及荧光特性的影响,随着氢分压下降,薄膜中氧含量升高,荧光峰强度增加,但位置不变;而荧光带在强度增加的同时,中心位置产生红移。根据实验结果对荧光起源及变化机制进行了     

多重谱线拟合（MSF）扣除光谱干扰法在电感耦合等离子体发射光谱？…

在用用电感耦合等离子体发射光谱法测定钢铁中磷时,已有的研究报告中大多采用Ｐ１７８ｎｍ作分析谱线,但因其发射强度低而使测定精度和检出限不理想。本文在采用多重谱线拟合（ＭＳＦ）法扣除光谱干状的基础上,测定了存在严重光谱干扰的Ｐ２１４ｎｍ、Ｐ２１３ｎｍ谱线,同时测定了没有光谱干扰的Ｐ１７８ｎｍ,Ｐ１７７ｎｍ谱线,结果表明,Ｐ２１３ｎｍ谱线的测定精密度和检出限最好,比常用Ｐ１７８ｎｍ谱线的精密精密度高５倍     

低压MOCVD生长GaN p—n结蓝光LED

简要报道了采用一种改进的低压金属有机化物化学气相沉积（ＬＰ－ＭＯＣＶＤ）方法制备ＧａＮｐ－ｎ结蓝光光发射二极管（ＬＥＤ），介绍了ＬＥＤ的基本特性，这种ＬＥＤ具有良好的Ｉ－Ｖ特性和光谱特性，室温下，在正向电压５Ｖ，正向电流３－２０ｍＡ的条件下，峰值波长为依Ｍｇ的掺杂浓度和退火条件的不同而不同，分别在４２５ｎｍ，４３５ｎｍ和４８０ｎｍ附近，发射谱的半峰宽约为５０ｎｍ。     

硅衬底阳极氧化铝膜的荧光发射研究

报道了用电子束蒸发技术在硅守底上沉积，并于１５ｗｔ％Ｈ２ＳＯ４，温度２５℃和４０Ｖ直流电压条件下阳极氧化铝薄的制备（膜厚约４００ｎｍ）。研究了该阳极氧化铝膜的红外吸收光谱（ＦＴＩＲ）、光致荧光光谱（ＰＬ）和荧光激发光谱（ＰＬＥ）。发现其荧光光谱在２８０￣５００ｎｍ范围内由三个主发射带组成，其峰值分别位于３１２ｎｍ，３６７ｎｍ和４４９ｎｍ。所有这三个ＰＬ带，经分析都与阳极氧化铝膜中的氧化铝膜中的氧空     

配位微环境对Hg(Ⅱ)-血清白蛋白结构的影响

详细研究了等点附近Ｈｇ－ＨＳＡ或ＢＳＡ体系的紫外光谱。与生理ｐＨ时的谱图相比较，Ｈｇ－ＢＳＡ的２５０ｎｍ附近谱带消失或变弱，而２９０ｎｍ谱带及Ｈｇ－ＨＳＡ的光谱基本不变。这一差异进一步支持了Ｈｇ离子在ＨＳＡ或ＢＳＡ中最可能的结合位置在７对相邻的二硫桥处，金属中心有四面体型ＭＳ４结构的推断。     

265—285nm范围内PCl3光解机理

利用可调谐染料激光,对ＰＣｌ３在２６５－２８５ｎｍ范围内的光解机理进行了研究。发现在２６５－２８５ｎｍ范围内光解ＰＣｌ３所获得的荧光发射谱基本相同,但在强度上有较大差别,在３８９．４３１和４８８ｎｍ处观察到明显的荧光发射,这些荧光来自ＰＣｌ３双光子解离产生的碎片ＰＣｌ激光态的发射,其中４８８ｎｍ处的荧光来自ＰＣｌ（Ａ→Ｘ）的跃迁,而３８９和４３１ｎｍ处的荧光可能来自ＰＣｌ的尚未报道地宾一新的单重诚     

有机薄膜在平面光学微腔中的光致发光特性

本文研究了有机薄膜在平面光学微腔中的光致发光特性。有机光学微脸以多层介质膜和金属银分别作为反射镜,８－羟基喹啉铝（Ａｌｑ）为发光层。Ａｌｑ薄膜的荧光峰位于５１９ｎｍ,谱线的半高全宽为９０ｎｍ。微腔的荧光峰位于５３０ｎｍ,谱线的半高全宽窄化至１０ｎｍ。谐振波长处的发射强度提高了一个数量级。     

Atomic thallium laser and Tl-Hg excimer formation by two photon dissociation of TlI and Hg mixtures

TlI vapor is photodissociated in a two photon process using 249 nm and 351 nm excimer laser radiation. In the presence of Hg buffer gas, stimulated emission of atomic Tl at 535 nm and broadband Tl-Hg excimer emission are observed. Dynamics of this process with possible implications for an optically pumped Tl-Hg excimer laser are discussed.     

Violet Band Excimer Emission of Zn_2 Excited by Relativistic Electron Beam

ＶｉｏｌｅｔＢａｎｄＥｘｃｉｍｅｒＥｍｉｓｉｏｎｏｆＺｎ２ＥｘｃｉｔｅｄｂｙＲｅｌａｔｉｖｉｓｔｉｃＥｌｅｃｔｒｏｎＢｅａｍＸＩＮＧＤａ１）ＷＡＮＧＱｉ２）ＴＡＮＳｈｉｃｉ１）Ｋｅｎ－ｉｃｈｉＵｅｄａ３）（１）ＩｎｓｔｉｔｕｔｅｏｆＬａｓｅｒＬｉｆ...     

A source of UV radiation based on pulsed discharge in a Xe-NaCl mixture

The design and operation parameters of an excimer lamp on a Xe-NaCl mixture are described. The emission spectrum of the lamp and its temporal characteristics are described. The XeCl excimer band at 308 nm dominates in the spectrum. The spectral distribution of energy within the band and its dependence on the experimental conditions are studied. The mechanism of excitation of the upper state of the excimer molecule is discussed.     

Investigation of Abnormal Long‐Wavelength Fluorescence Emissions Occurring in Binary Organic Nanoparticle Films

In some fluorophores with planar groups, a long‐wavelength emission band different from their native one can sometimes be observed. The main cause of this long‐wavelength band is excimer formation. It is generally accepted that once condensed in the solid state, whether fluorophores can exhibit excimer emission or not depends only on their molecular structure and packing. However, here it is shown that there are exceptions when fluorophores are present in nanoparticles (NPs), where excimer emission can be affected by the environment surrounding the NPs, even in the solid state. It is found that in some binary NP films consisting of fluorophore NPs and other NPs, unusual long‐wavelength bands ascribed to excimer emission can be activated, even though these bands are absent from the photoluminescence spectra of the pure fluorophore NP films. This finding is beneficial to better understand and control excimer emissions. In addition, such a binary NP system provides an ideal platform to investigate the interplay between two fluorophores, because it keeps them effectively separated while maintaining suitable spatial distances for exciton migration and dipole–dipole interactions. This work also provides evidence for the long‐debated origin of the green emission band (g‐band) of fluorene‐based fluorophores.     

Narrowband emission of argon dimers in a dc discharge with supersonic expansion

Narrowband emission of Ar₂ ^* at 126 nm was observed in a dc discharge with supersonic expansion and cooling of Ar gas through a metallic nozzle. The bandwidth of the excimer emission was 5.7 nm, which was lower than the values reported in the literature. The short bandwidth was attributed to the increased contribution of the singlet excimer state to the emission that could lead to a partial amplification of the radiation. PACS 33.20.Ni; 42.55.Lt; 52.80.Yr     

An anomalous emission excited near the absorption edge of pyrene crystals

Emission spectra and decay times of the fluorescence excited at the absorption edge region in pyrene crystals were measured. At liquid nitrogen temperature, the fluorescence under the excitation at 390 nm is considered as the excimer emission and its band peak shifts a little to the short wavelength in comparison with that of the excimer emission under the excitation at 360 nm. The emission decay times under the excitation at the 390 nm and 360 nm are about 155 ns and 180 ns, respectively, at liquid nitrogen temperature. The former decay time changes its value abruptly near 127 K. This abrupt change of the decay time may be due to the phase transition in pyrene crystals.     

LnZr(BO3)2:Eu3+(Ln=Ba,Sr)的真空紫外光谱特性的研究

采用高温固相法合成了Ba(1-x)SrxZr(BO3)2:Eu3 系列样品,样品Ba(1-x)SrxZr(BO3)2:Eu3 激发谱在130～170nm和230 nm区域有两个很强的吸收带,位于130～170nm的吸收带主要是硼酸盐基质的吸收;位于230nm附近的吸收主要是Eu3 电荷转移态的吸收.当在样品中以Al部分取代Zr时,电荷转移态的吸收明显增强,并且Ba(1-x)SrxZr(BO3)2:Eu3 发射强度也会明显增强;随着x的增大,硼酸盐基质的吸收强度减弱,基质吸收带的主峰值向低能方向移动了大约30 nm.样品Ba(1-x)SrxZr(BO3)2:Eu3 在147nm激发下,发射出主峰值位于616nm的强红光,对应Eu3 电偶极(5D0→7F2)跃迁发射.     

Photophysics of 9-aminoacridinium hydrochloride

The steady state and time domain spectroscopy of 9-aminoacridinium hydrochloride have been studied. 9-aminoacridine (I), 9-aminoacridinium (II) and the double protonated ion (III) follow Waterman’s principle with respect to their spectra and lifetimes. It is established that the excimer formation in (II) is from the ground state dimers which undergo either thermally-activated radiationless excimer conversion or a geometrical rearrangement in the excited state at room temperature. The quenching of monomer emission by dimers or foreign quenchers (KI) is found to be of transient nature as suggested by the continuum model. The authors felicitate Prof. D S Kothari on his eightieth birthday and dedicate this paper to him on this occasion.     

Optical properties of silicon microcolumn grown by nanosecond pulsed laser irradiation

We have investigated the optical properties of silicon pillars formed by cumulative nanosecond pulsed excimer laser irradiation of single-crystal silicon in vacuum created under different repetition rates. The changes in optical characteristics of silicon pillar were systematically determined and compared as the number of KrF laser shots was increased from 1 to 15,000.The results show that silicon pillar PL curves exhibit a blue band around 430 nm and an ultraviolet band peaking at 370 nm with the vanishing of the green emission at 530 nm. A correlation between the intensity of the blue PL band and the intensity of the Si-O absorption bands has been exploited to explain such emission, whereas, the origin of the ultraviolet band may be attributed to different types of defects in silicon oxide.     

Blue-to-Orange Tunable Luminescence from Europium Doped Yttrium--Silicon--Oxide--Nitride Phosphors

Europium-doped yttrium-silicon-oxide-nitride phosphors are synthesized by carbothermal reduction and nitridation method. The crystal structure of the phosphors changed gradually from oxide Y2Si2O7 to nitride YSi3N5 state with increasing dosage of Si3N4 and carbon powder. The Y2Si2O7：Eu phosphor shows a blue emission at 465 nm with 300 nm excitation and a characteristic red emission of Eu^3＋ at 612 nm with 230 nm excitation. The YSi3N5：EU phosphor shows a broad emission band centred at 595nm with some sharp peaks of Eu^3＋ with 325nm excitation. The absorption of the studied phosphors increases from 450 to 700hm with an increment in nitrogen content. Blue-to-orange tunable luminescence is observed with 390 nm excitation.