基于垂直结构的有机光发射晶体管制备与性能研究

制备了一种有机垂直光发射晶体管, 兼具有机发光二极管的发光和晶体管的开关调节两个功能.其结构为一个有机发光单元垂直堆叠在一个电容单元上,两单元通过一个共有的源电极连在一起.当电容单元被充电时,积累在源电极的电荷能有效地调节源极与有机层之间的载流子注入势垒,从而达到控制源漏输出电流的大小,最终控制发光单元发光的强度.实验结果表明,器件可提供02 mA的输出电流,其大小可驱动发光单元发光,工作电压（开启电压）为6 V.这种垂直集成方案,实现了器件多功能化,为有机发光二极管有源矩阵驱动的实际应用提供了一种新的解决方法. 关键词： 有机光发射晶体管 垂直 电容     

基于NPB的垂直构型有机发光晶体管的光电特性研究

通过将有机空穴阻挡材料BCP薄层插入垂直构型有机发光晶体管器件ITO/NPB（40nm）/Al（30nm）/NPB（20nm）/Alq₃（55nm）/Al中的不同位置对器件光电特性的影响来研究器件漏电流较大的原因以及器件中具体的载流子过程.充分证明了栅极注入的空穴对沟道中的电流有贡献.进而通过用LiF薄层修饰漏极来增强电子的注入并减小漏电流,得到了相对稳定的发光晶体管器件,其发光强度有很大提高并可很好地由栅极电压来进行调控.更换发光材料层容易得到不同颜色的发光晶体管. 关键词： 垂直构型有机发光晶体管（VOLET） 静电感应晶体管（SIT） N')" href="#">NPB （N N′-diphenyl-N')" href="#">N′-diphenyl-N N′-bis（1-naphtyl）-1')" href="#">N′-bis（1-naphtyl）-1 1′-biphenyl-4     

基于LPC2210和SSD1339的PM-OLED驱动控制电路

为了避免早期无源矩阵有机电致发光器件驱动控制电路的一些缺陷,如:"串扰"和"交叉"效应以及电路连接比较复杂,用两种方法实现了基于飞利浦公司生产的LPC2210控制芯片和晶门科技公司的SSD1339驱动芯片的驱动控制电路。首先介绍了有机电致发光器件的结构和发光原理以及芯片SSD1339和LPC2210的主要的特点;分析和比较了SSD1339的8080系列并行口和LPC2210外部存储控制单元的读写时序;分别利用LPC2210的通用输入输出单元和外部存储控制单元,成功的控制SSD1339驱动128RGB×128点阵有机电致发光屏。实验结果表明:两种方法不仅可以有效地克服早期驱动控制电路的缺陷,而且可以使有机电致发光屏显示出高质量的图片;用外部存储控制单元实现的驱动控制电路,可以实现约80 Hz的驱动帧频;而使用通用输入输出单元实现的驱动控制电路,可以单步跟踪数据的传输,因此它具有方便查错的优势。本次实验为在不同的集成环境下无源矩阵有机电致发光器件驱动控制电路的设计奠定基础。     

非晶硅碳薄膜发光二极管发光的热致猝灭

本文详细测试了用RF-PECVD法制备的非晶硅碳薄膜发光二极管的光强电流特性和温度对器件发光强度的影响.在直流电流驱动下,器件的发光在注入电流1A/cm2左右趋于饱和,而在低占空比的脉冲电流驱动下器件的发光直至注入电流20A/cm2仍随电流近似线性增长,但提高环境温度发光随之下降.结合对器件受热情况分析表明,热致猝灭而非场致猝灭导致了器件在大电流下的发光饱和,并简要提出了改进器件散热的措施.     

微电流高效率650nm谐振腔发光二极管

基于微腔理论和薄膜光学传输矩阵模型,设计并制备了孔径不同的谐振腔发光二极管.通过对外延结构的设计和对器件的制备与测试,详细研究了微腔结构、腔谱失谐以及有效辐射面积对器件发光效率、峰值波长和半波全宽等性能的影响,最终降低了器件的启亮电流并且提升了器件的外量子效率.制备的器件能够在100μA偏置电流下产生肉眼清晰可见的微瓦级光强,在1mA电流下达到0.16mW的光功率和7%的外量子效率.器件的峰值波长为650nm,并且在0.1~7mA范围内不随电流改变而发生变化.远场分布为均匀对称的圆形光斑,水平和竖直发散角分别为46°和48°.与普通发光二极管相比,该器件具有更高的发光效率和更好的单色性、方向性、波长稳定性,研究成果为实现微小电流驱动的高亮度发光器件提供了基础元件,并为谐振腔发光二极管在微电流下的光电特性研究提供参考与借鉴.     

莱纳(发光、接收光器件)

莱纳的概况 “LANER”(莱纳)是一种具有开关和发光两种性能的光半导体器件。这个单一的器件,同时具有接收光和发光的机能。它不但具有非线性特性(或负阻特性)控制机能,同时还能用可见光、红外线或同时用这两种光的波长来驱动控制。莱纳不仅可以在常温下工作,并且还可用莱纳中发光二极管的输出光来驱动器件本身。因此,实现了所说的“光的互相作用”。     

蓝色荧光有机发光二极管中的激子-电荷相互作用

有机发光二极管(OLED)作为新一代显示技术已广泛商用,但蓝光有机发光二极管在效率和稳定性等方面仍存在不足,虽用磷光染料能明显地提高效率,其制作成本之高却限制了产业化发展.因此,本文对蓝色荧光有机发光二极管中的效率滚降现象进行了深入探究.首先,从稳态和瞬态两个角度研究了电子电流和空穴电流对单极器件光致发光行为的影响,表明空穴对激子的淬灭效果更显著.实验证明激子-电荷相互作用是荧光OLED中效率滚降的主要机制,且激子主要是被束缚电荷淬灭而非移动电荷.另一方面制备了不同掺杂浓度的有机发光二极管器件以探究掺杂浓度对激子-极化子相互作用的影响,得到了综合性能较好的蓝色有机荧光器件,分析表明调控发光层电荷俘获可以平衡界面堆积电荷和发光层束缚电荷对激子的淬灭.本文完善了激子-极化子淬灭的内在机制,给减缓蓝色荧光有机发光二极管的效率滚降提供了有益参考.     

基于自动跟踪LED驱动电压控制电路的创新设计

LED发光二极管在发光时约有80%以上的功率转化成了热能,导致LED发光二极管的PN结温度过高,这是影响LED发光二极管的发光效率与照明功能的主要因素。本文针对上述问题,结合现实情况,设计了一种自动跟踪LED驱动电压的控制电路,从串联稳流单元采样一个电压信号,与本控制电路中的基准电压相比较,产生一个控制信号,去控制所述串联稳流单元前级的开关稳压电源,使它的输出电压随LED灯的工作电压的变化而变化,不增加调整管的功耗。避免了常见的恒压驱动亮度变化大的缺陷,从而大幅度提高LED发光二极管的工作效率,该控制电路结构简单、成本低、损耗小与可靠性高。     

不同加速层材料对固态阴极射线发光的影响

在固态阴极射线发光中,过热电子碰撞激发有机材料而发光,因此加速层对电子的加速能力是影响器件发光亮度的关键因素之一.分别以SiO2和ZnO作为加速层.制备出两种固态阴极射线发光器件A:ITO/MEH-PPV/SiO2/Al和B:ITO/MEH-PPV/ZnO/Al.通过理论计算比较了电子从电极注入到加速层的隧穿电流密度以及SiO2层与ZnO层的电场强度,计算结果表明:在相同驱动电压下,SiO2作为电子加速层时隧穿电流的密度要大于ZnO层的隧穿电流的密度,并且SiO2层的电场强度比ZnO层的电场强度大.实验结果表明:SiO2作为加速层的器件的发光强度高于以ZnO为电子加速层器件的发光强度.     

可调色红光有机电致发光器件

介绍了具有可调节发光光谱的高效红光有机发光二极管(OLED)器件,利用具有高三重态能量的9.9-螺二芴二苯基氧化磷(SPPO1)作为发光层的主体材料及空穴阻挡层,二(1-苯基异喹啉)(乙酰丙酮)合铱(III) (Ir(piq)2(acac))作为客体发光材料,在发光层内SPPO1的能量分别由福斯特和迪克斯特传递到Ir(piq)2(acac)的单重态和三重态从而发出红色磷光,通过调节磷光客体材料的比例得到最优器件结构,从而得到具有较好发光效率和发光亮度并可调节色纯的有机发光二极管器件。     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Characterization of PolyA and PolyC mismatches by Raman spectroscopy

A.C mismatches are studied by Raman spectral characterization of PolyA, PolyC, and their equimolar complex in solution of 0.14 mol/L Na ,pH7.0.Experimental results show that A·C mismatches occur to be A/B (mainly A) conformers, and unlike Watson-Crick base pairing, this kind of mismatches is stabilized by only one hydrogen bond involving cytosine N4H2 and adenine N7.The formation of A·C complex makes the base stacking interactions much stronger, and conformation of the backbone more ordered, which leads to obvious Raman hypochromic effect with some shifts in corresponding bands.     

Improvement of four-wave mixing-based wavelength conversion efficiency in dispersion shifted fiber by 40-GHz clock pumping

40-GHz clock modulated signal as a pump to improve the efficiency of four-wave mixing (FWM)-based wavelength conversion in a 26.5-km dispersion shifted fiber (DSF) is investigated. The experimental results demonstrate that the conjugated FWM component has higher intensity with the clock pumping than that with the continuous-wave (CW) light pumping. The improvement of FWM-based wavelength conversion efficiency is negligible when the pump power is less than Brillouin threshold. But when the pump power is greater than Brillouin threshold, the improvement becomes significant and increases with the increment of pump power. The improvement can increase up to 9 dB if pump power reaches 17 dBm.     

Multi-pulse operation of a Kerr-lens mode-locked femtosecond laser

Our experimental results show that the presence of a proper amount of negative group velocity dispersion is essential to multi-pulse operation of a Kerr-lens mode-locked femtosecond laser. We demonstrate that the pulse separations and the number of pulses contained within a cavity round trip are strongly dependent on the initial perturbations. The results allow us to get a better understanding on the influences of the convoluted self-phase modulation and intra-cavity dispersions on the stable multi-pulse oscillation in a Kerr-lens mode-locked femtosecond laser.     

Propagation of Helmholtz-Gauss beams in weak turbulent atmosphere

Based on the Rytov approximation of light propagation in weak turbulent atmosphere,the closed-form expressions of field and average irradiance of each one of the four fundamental families of Helmholtz-Gauss (HzG)beams:cosine-Gauss beams,stationary Mathieu-Gauss beams,stationary parabolic-Gauss beams,and Bessel-Gauss beams,which are propagating in weak turbulent atmosphere,are obtained.The results show that the field and average irradiance can be written as the product of four factors:complex amplitude depending on the z-coordinate only,a Ganssian beam.a factor of complex phase perturbation induced by atmospheric turbulence,and a complex scaled version of the transverse shape of the non-diffracting beam.The effect of weak atmospheric turbulence on irradiance distribution of the HzG beam can be ignored.     

An effective method for reducing speckle noise in digital holography

An effective method for reducing the speckle noise in digital holography is proposed in this paper.Different from the methods based on classical filtering technique,it utilizes the multiple holograms which are generated by rotating the illuminating light continuously.The intensity images reconstructed by a series of holograms generated by rotating the illuminating light possess different speckle patterns.Hence by properly averaging the reconstructed intensity fields,the speckle noises can be reduced greatly.Experimental results show that the proposed method is simple and effective to reduce speckle noise in digital holography.     

Influence of purity of HfO2 on reflectance of ultraviolet multilayer

The impurities in two kinds of HfO2 materials and in their corresponding single layer thin films were determined through glow discharge mass spectrum technology and secondary ion mass spectrometry(SIMS) equipment respectively.It was found that ZrO2 was the main impurity in the two kinds of HfO2 either in the original HfO2 materials or in the electron beam deposited films.In addition,the difference of Zr content in the two kinds of HfO2 single laver films was much laxger than that of the other impurities such as Ti and Fe.which showed that it was just ZrO2 that made the difference between the optical performance of the film products including the two kinds of HfO2.With these two kinds of HfO2 and the same kind of SiO2.we deposited HfO2/SiO2 multilayer reflective coatings at the wavelength of 266 nm.Experimental results showed that the reflectances of these two mirrors were about 99.85% and 99.15% respectively,which agreed well with the designed results what were based on the optical constants obtained from the corresponding single layer thin films.     

Speech enhancement by array crosstalk resistant ANC and spectrum subtraction

Microphone array-based speech enhancement has great importance for speech communications and speech recognition. To reduce the aperture of the microphone array and to increase the effect of the speech enhancement will greatly broaden the application areas of the microphone array. An array crosstalk resistant adaptive noise cancellation method is therefore presented. And then an improved spectral subtraction algorithm is further cascaded to obtain better enhancement results. Theoretic analysis and experiments indicate that the proposed scheme needs only a very small microphone array while it simultaneously achieves a higher SNR improvement. Besides, the proposed scheme can be used in many noisy environments and is easy for real-time implementation.