用于等离子体电位测量的电容探针和发射探针

本文给出了发射探针和电容探针测量等离子体电位的实验和方法。发射探针采用直流功率加热，并在较强电子发射条件下运行（Ｉ_（ｅ０）／Ｉ_（ｅ０）＞１）。电容探针表面二次电子发射系数δ≥１。本文对发射探针的电子发射性能、工作电流、电容探针的输入、输出电压关系进行了标定实验。得到了电容探针的校准系数分别为３×１０（－３）、５×１０（－４）。实验给出了ＭＭ－４会切中心等离子体电位Ｖ_（ｐ４）＝－８２±９－１２２±１２Ｖ；ＭＭ－４Ｕ东、西会切中心等离子体电位分别为Ｖ_（Ｐ４ｕ１）＝－５２．９±３．２Ｖ，Ｖ_（Ｐ４ｕ２）＝－６２±３．２Ｖ。     

NH4Cl作助熔剂合成CaS：Ce的光谱特性及其浓度效应

以ＮＨ４Ｃｌ作助溶剂，碳还原硫酸钙的方法合成了ＣａＳ：Ｃｅ。在紫外光激发下，ＣａＳ：Ｃｅ中存在着Ｃｅ＾３＋的＾２Ｄ－＾２Ｆ５／２（５００ｎｍ）和＾２Ｄ－＾２Ｆ７／２（５５０ｎｍ）跃迁发射，但在蓝色光激发下，只有波峰为５３２ｎｍ半宽度为９２ｎｍ的宽带发射。当Ｃｅ＾３＋的浓度为０．０７５ｍｏｌ％时，＾２Ｄ－＾２Ｆ５／２跃迁发射强度与＾２Ｄ－＾２Ｆ７／２跃迁发射强度相等，而５３２ｎｍ发射猝灭。     

ZnCdse－ZnSe多量子阱中的激子发光

在７７－３００Ｋ温度下研究了Ｚｎ（１－ｘ）ＣｄｘＳｅ－ＺｎＳｅ多量子阱（ＭＱＷｓ）的光致发光特性．首次在７７Ｋ，Ａｒ离子激光器的４５７．９ｎｍ激发下，在Ｚｎ（０．６８）Ｃｄ（０．３２）Ｓｅ－ＺｎｓｅＭＱＷｓ中观测到５个发光带，其中三个发光带被归因于不同的激子发射：即ｎ＝１重空穴（ＨＨ）激子；ｎ＝ｌ轻－重空穴（ＬＨ）激子和ｎ＝ＩＨＨ激子同时发射两个纵光学声子的复合发光，并且，；ｎ＝１ＨＨ激子发光可延续至室温．     

掺杂聚合物蓝光发光二极管

报道了用有机染料ＴＰＢ（１，ｌ，４，４－四苯基丁二烯）分散到ＰＶＫ（聚乙烯基咔唑）中的掺杂聚合物作有源层制作的蓝光发光二极管及其发光特性。聚合物发光层用旋转涂敷的方法制备，用透明导电材料ＩＴＯ（铟锡氧化物）、金属Ａｌ作为正负电极。器件正向偏压为１３Ｖ时，可以看到蓝光发射，峰值波长为４５５ｎｍ，注入电流为５０ｍＡ／ｃｍ２时，亮度为４４ｃｄ／ｍ２。     

一种压控波长可调谐异质结有机薄膜发光二极管

利用空穴型聚合物材料ＲＯＰＰＶ－１２［聚（十二烷氧基－对苯乙炔）］与电子型有机小分子材料Ａｌｑ３（八羟基喹啉铝）配合制备了有机薄膜异质结发光二极管。发现该异质结器件在ＲＯＰＰＶ－１２的厚度保持为７０ｎｍ、Ａｌｑ３的厚度为２０ｎｍ时，器件的性能最优，且电致发光完全来自ＲＯＰＰＶ－１２；而当Ａｌｑ３的厚度为３２ｎｍ时，发光区域则跨越了ＲＯＰＰＶ－１２与Ａｌｑ３，器件在较低驱动电压下来自ＲＯＰＰＶ－１２的光发射占主导地位，随着电压的升高，Ａｌｑ３的光发射逐渐占据了主导地位。在相同电压下，前一器件的亮度、电流、发光效率都要远高于后一器件。分析了其发光机理。     

染料激光泵浦Nd：S－VAP晶体激光特性研究

实验测定了Ｎｄ：Ｓｒ５（ＶＯ４）３Ｆ（简称Ｎｄ：Ｓ－ＶＡＰ）晶体的吸收光谱特性；在５８３．０ｎｍ和８０９．０ｎｍ处有强的吸收峰。用可调谐染料激光作泵浦源，实现了低阈值、高效率的激光运转。在透射率１５％的平面平行腔情况下，斜率效率为５０％，阈值为２ｍＪ。倍频光中心波长为５３６．０ｎｍ，线宽为１．４ｍｍ。本文还对Ｎｄ：Ｓ－ＶＡＰ晶体可作为ＬＤ泵浦的小型激光器的工作物质等问题进行了讨论。     

Br^—2,Cl^—2.诱导氧化磷酰化甲硫氨酸水溶液的脉冲辐解研究

采用脉冲辐解动态吸收光谱法研究了Ｂｒ＾－２和Ｃｌ＾－２自由在诱导氧化Ｎ－二异丙基磷酰化甲硫氨酸（ＮＤＭ）水溶液的过程，结果表明：Ｂｒ＾－２和Ｃｌ＾－２进攻ＮＤＭ中的硫原子形成含硫三电子键ＮＤＭ（Ｓ∴Ｘ）（Ｘ＝Ｂｒ，Ｃｌ）它们分别在４００ｎｍ和３９０ｎｍ处有最大吸收峰，形成和衰变均呈一级反应，测定了不同条件下氧化反应的速率常数，推导了反应机理，并从分子结构观点与甲硫氨酸水溶液的Ｂｒ＾－２．Ｃｌ＾－２     

具有纯Tb^3＋发光光谱的有机电致发光二极管

制成了用三价Ｔｂ配合物作为发射层的有机电致发光二极管，并获得纯Ｔｂ３＋的发光光谱。二层结构为玻璃衬底／Ｉｎ－ＳｎＯ（ＩＴＯ）／ｐｏｌｙ（Ｎ－ｖｉｎｙｌｃａｒｂａｚｏｌｅ）（ＰＶＫ）／Ｔｂ配合物／Ａｌ，在正向直流偏压下发出明亮的绿光。器件的电致发光（ＥＬ）光谱与Ｔｂ配合物薄膜的光致发光（ＰＬ）光谱完全一致，含有一个尖锐的发射带，系典型的Ｔｂ配合物的发光谱。在驱动电压为５Ｖ下，发光清晰可见，当驱动电压达到１５．４Ｖ时，获得２１０ｃｄ／ｍ２的发光，据知这是用Ｔｂ配合物做发射层的电致发光元件的最亮的发光。同时，通过对器件光谱及电学特性的测量、比较和分析，探讨了有关稀土电致发光机理等问题     

染料激光泵浦Nd：S—VAP晶体激光特性研究

实验测定了Ｎｄ：Ｓｒ５（ＶＯ４）３Ｆ晶体的吸收光谱特性；在５８３．０ｎｍ和８０９．０ｎｍ处有强的吸收峰。用可调谐染料激光作泵浦源，实现了低阈值、高效率的激光运转。在透射率１５％的平面平行腔情况下，斜率效率为５０％，阈值为２ｍＪ。倍频光中心滤长为５３６．０ｎｍ，线宽为１．４ｍｍ。本文还对Ｎｄ：Ｓ－ＶＡＰ晶体可作为ＬＤ泵浦的小型激光器的工作物质等问题进行了讨论。     

5—溴水杨基荧光酮—溴化十六烷基三甲铵荧光熄灭法测定微量？…

本文报道了在溴化十六烷基三甲铵（ＣＴＭＡＢ）存在下,以５－溴水杨基荧光酮（５－ＢrＳＡＦ）作为荧光试剂,用荧光熄灭法测定微量钼的新方法。详细研究了各种条件实验。 反应了适宜酸度范围为０．０８－０．２４ｍｏｌ．Ｌ＾－１ＨＣ１,钼含量在０－４．０ｕｇ／２５ｍＬ范围内呈线性关系,配合物的组成比为Ｍo（Ⅳ）：５－ＢrＳＡＦ：ＣＴＭＡＢ＝１：２：２,激发波长为３６５ｎｍ,发射波长为５２５ｎｍ。方法灵敏度高,检出     

Recent progress in single chip white light-emitting diodes with the InGaN underlying layer

Tremendous progress has been achieved in white light-emitting diodes (LEDs). To further improve the quality of white light and simplify the fabrication process, a single chip white-light LED with the InGaN underlying layer (UL) was studied and fabricated. The turn-on voltage of this type of LED was 2.7 V, and the spectrum at a forward bias current of 20 mA was comprised of blue (443 nm) and yellow (563 nm) lights. The intensity ratio of blue to yellow light was almost constant with the in- creasing injectio...     

注入电流对绿光高压LED光电特性的影响

设计并制备了12 V 的GaN基绿光高压发光二极管（LED）,并对其进行了变电流测试。研究了绿光高压LED的正向电压、峰值波长、光功率以及光效等重要参数随注入电流的变化关系,电流变化范围为3~50 mA,测试温度为25 ℃。实验结果表明：电流对绿光高压LED的光电特性有很大影响。在驱动电流为20 mA时,对应电压为14 V。随着注入电流的增大,峰值波长蓝移了2 nm。随着电流的增大,光功率近似于线性增加。在注入电流从3 mA增大到20 mA的过程中,光效降低了约61%;在注入电流从20 mA增大到50 mA的过程中,光效降低了约39%。这说明高压LED在大电流驱动时,光效降低的幅度比较缓慢。上述结果对 GaN基绿光高压 LED 的改进优化具有一定的参考价值。     

Realization of Ultraviolet Electroluminescence from ZnO Homojunction Fabricated on Silicon Substrate with p-Type ZnO:N Layer Formed by Radical N2O Doping

ZnO homojunction light-emitting diodes are fabricated on Si（100） substrates by plasma assisted metal organic chemical vapour deposition. A p-type layer of nitrogen-doped ZnO film is formed using radical N2O as the acceptor precursor. The n-type ZnO layer is composed of un-doped ZnO film. The device exhibits desirable rectifying behaviour with a turn-on voltage of 3.3 V and a reverse breakdown voltage higher than 6 V. Distinct electrolumineseence emissions centred at 395nm and 490nm are detected from this device at forward current higher than 20mA at room temperature.     

ITO界面调制层对GZO电极LED器件性能的影响

采用磁控溅射制备GZO和具有ITO界面调控层的GZO(ITO/GZO)透明导电薄膜作为大功率LED的电流扩散层,对比研究界面调控层对LED器件性能的影响。研究结果表明,ITO/GZO薄膜的透过率在可见光区达80%以上,退火后的ITO/GZO薄膜有较低的电阻率(1.15×10^-3 Ω·cm)。ITO调控层的介入能够调制GZO表面粗糙度,有利于改善LED外量子效率,降低GZO/p-GaN界面的接触势垒,提高LED器件的光电性 能。通过ITO界面调控后,LED器件20 mA驱动电流下的工作电压从9.5 V降低为6.8 V,发光强度从245 mcd 升到297 mcd,提高了20%;驱动电流为35 mA时,其发光强度从340.5 mcd 升到511 mcd,提高了50%。     

表面InGaN厚度对GaN基发光二极管特性的影响

通过调整GaN基发光二极管(LED)表面InGaN层的厚度,发现在20 mA电流驱动下,LED器件的正向压降有明显差距.本文考虑了极化效应的影响,通过求解InGaN/GaN三角形势阱内二维空穴气浓度以及空穴隧穿概率的变化,求得了表面InGaN层厚度不同时器件正向压降的变化趋势,发现理论结果与实验结果有很好的吻合.同时得到了获得最低正向压降的表面InGaN厚度. 关键词： 极化 二维空穴气 隧穿概率     

表面InGaN厚度对GaN基发光二极管特性的影响

通过调整GaN基发光二极管(LED)表面InGaN层的厚度，发现在20 mA电流驱动下，LED器件的正向压降有明显差距.本文考虑了极化效应的影响，通过求解InGaN/GaN三角形势阱内二维空穴气浓度以及空穴隧穿概率的变化，求得了表面InGaN层厚度不同时器件正向压降的变化趋势，发现理论结果与实验结果有很好的吻合.同时得到了获得最低正向压降的表面InGaN厚度.     

MOCVD生长InGaN/GaN MQW紫光LED

利用LP－MOCVD系统生长了InGaN/GaN MQW紫光LED外延片，双晶X射线衍射测试获得了2级卫星峰，室温光致发光谱的峰值波长为399.5nm，FWHM为15.5nm，波长均匀性良好。制成的LED管芯，正向电流20mA时，工作电压在4V以下。     

Non-polarized memory effect in amorphous point-contact diodes driven by currents smaller than 0.5 mA

A reliable memory effect in point-contact diodes, which is independent of the polarity of driving voltage and strongly dependent on the material of the electrodes, has been observed. Antimony and As₂S₃ were the most appropriate for the point-contact electrode and the amorphous thin film respectively. The diodes could be driven by current smaller than 0.5 mA.     

Enhanced output power for InGaAlP LEDs by contact-transferred and mask-embedded lithography

The authors applied a simple, low-cost, mass-producible contact-transferred and mask-embedded lithography (CMEL) to texture p-GaP window layer for the fabrication of InGaAlP light-emitting diodes (LEDs) emitting at 612 nm. Under 20 mA current injection, it was found that forward voltages were 2.25, 2.24 and 2.25 V for CMEL-400 nm LED, CMEL-2 μm LED and the conventional LED without CMEL, respectively. It was also found that the 20 mA output powers were 1.43, 1.28 and 1.16 mW for CMEL-400 nm LED, CMEL-2 μm LED and the conventional LED without CMEL, respectively.     

High power and high reliability GaN/InGaN flip-chip light-emitting diodes

High-power and high-reliability GaN/InGaN flip-chip light-emitting diodes (FCLEDs) have been demonstrated by employing a flip-chip design, and its fabrication process is developed. FCLED is composed of a LED die and a submount which is integrated with circuits to protect the LED from electrostatic discharge (ESD) damage. The LED die is flip-chip soldered to the submount, and light is extracted through the transparent sapphire substrate instead of an absorbing Ni/Au contact layer as in conventional GaN/InGaN LED epitaxial designs. The optical and electrical characteristics of the FCLED are presented. According to ESD IEC61000-4-2 standard (human body model), the FCLEDs tolerated at least 10\,kV ESD shock have ten times more capacity than conventional GaN/InGaN LEDs. It is shown that the light output from the FCLEDs at forward current 350mA with a forward voltage of 3.3\,V is 144.68\,mW, and 236.59\,mW at 1.0\,A of forward current. With employing an optimized contact scheme the FCLEDs can easily operate up to 1.0\,A without significant power degradation or failure. The life test of FCLEDs is performed at forward current of 200\,mA at room temperature. The degradation of the light output power is no more than 9\% after 1010.75\,h of life test, indicating the excellent reliability. FCLEDs can be used in practice where high power and high reliability are necessary, and allow designs with a reduced number of LEDs.