高分辨率蓝光光学显微测量系统

本系统用波长为405nm的超亮度蓝色发光二极管作为光学显微镜的照明光源，结合CCD图像传感技术和图像采集技术，实现了对显微图像的实时观察和存取的计算机化。观察到的DVD盘片的清晰显微图像表明，其光学分辨率优于400nm。运用自编的图像分析软件对采集到的CD RW光盘图像进行分析和标定，测定其道间距为1.6μm。因此，本系统在显微观测领域，特别是对观测和分析接近普通光学显微镜分辨极限尺寸的微结构，有重要的实用价值。     

Synthesis and electrochemical and electroluminescent properties of N‐phenylcarbazole‐substituted poly(p‐phenylenevinylene)

An N‐phenylcarbazole‐containing poly(p‐phenylenevinylene) (PPV), poly[(2‐(4′‐carbazol‐9‐yl‐phenyl)‐5‐octyloxy‐1,4‐phenylenevinylene)‐alt‐(2‐(2′‐ethylhexyloxy)‐5‐methoxy‐1,4‐phenylenevinylene)] (Cz‐PPV), was synthesized, and its optical, electrochemical, and electroluminescent properties were studied. The molecular structures of the key intermediates, the carbazole‐containing boronic ester and the dialdehyde monomer, were crystallographically characterized. The polymer was soluble in common organic solvents and exhibited good thermal stability with a 5% weight loss at temperatures above 420 °C in nitrogen. A cyclic voltammogram showed the oxidation peak potentials of both the pendant carbazole group and the PPV main chain, indicating that the hole‐injection ability of the polymer would be improved by the introduction of the carbazole‐functional group. A single‐layer light‐emitting diode (LED) with a simple configuration of indium tin oxide (ITO)/Cz‐PPV (80 nm)/Ca/Al exhibited a bright yellow emission with a brightness of 1560 cd/m² at a bias of 11 V and a current density of 565 mA/cm². A double‐layer LED device with the configuration of ITO/poly(3,4‐ethylenedioxy‐2,5‐thiophene):poly (styrenesulfonic acid) (60 nm)/Cz‐PPV (80 nm)/Ca/Al gave a low turn‐on voltage at 3 V and a maximum brightness of 6600 cd/m² at a bias of 8 V. The maximum electroluminescent efficiency corresponding to the double‐layer device was 1.15 cd/A, 0.42 lm/W, and 0.5%. The desired electroluminescence results demonstrated that the incorporation of hole‐transporting functional groups into the PPVs was effective for enhancing the electroluminescent performance. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5765–5773, 2005     

Poly(p‐phenylenevinylene) presenting pendent pentaphenylene dendron groups for light‐emitting diodes

We have synthesized, using the Gilch method, a novel poly(p‐phenylenevinylene) derivative (PPV‐PP) containing two pendent pentaphenylene dendritic wedges, and have characterized its structure and properties. The incorporated side chain pentaphenylene dendrons serve as solubilizing groups, prevent π‐stacking interactions from occurring between the polymer main chains, and suppress the formation of excimers in the solid state. Photoluminescence studies indicate that efficient intramolecular energy transfer occurred from the photoexcited pentaphenylene groups to the poly(p‐phenylenevinylene) backbone. The polymer film exhibits a maximum emission at 510 nm and had a photoluminescence efficiency of 46%, which is similar to that measured in dilute solution. The photoluminescence spectra remained almost unchanged after thermal annealing at 150 °C for 20 h, and displayed inhibited excimer formation. Polymer light‐emitting diodes that we fabricated in the configuration ITO/PEDOT/PPV‐PP/Mg:Ag/Ag exhibited a maximum emission peak at 513 nm, corresponding to the green region [x = 0.30 and y = 0.62 in the Commission Internationale de L'Eclairage (CIE) chromaticity coordinates]. The maximum brightness and maximum luminance efficiency were 1562 cd/m² and 1.93 cd/A, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5147–5155, 2005     

Synthesis of conjugated copolymers containing phenothiazinylene vinylene moieties and their electrooptic properties

Four different types of conjugated copolymers, consisting of alternating structures of phenothiazinylene vinylene and phenylene vinylene derivatives such as phenylene vinylene, 1,1′‐biphenyl‐4,4′‐ylene vinylene, 2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylene vinylene, and 9,10‐anthrylene vinylene, were prepared by Horner–Emmons condensation between appropriate diphosphonates and dialdehydes. Single‐layer and double‐layer light‐emitting diodes were fabricated with the synthesized conjugated polymers, and their electroluminescent properties were investigated. Poly(N‐2‐ethylhexyl‐3,6‐phenothiazinylene vinylene‐alt‐9,10‐anthrylene vinylene), containing phenothiazinylene vinylene and anthrylene vinylene as repeat units, emitted a reddish‐orange color with Commission Internationale de l'Eclairage coordinates of x = 0.6173 and y = 0.3814 that was very similar to the National Television System Committee standard red, and it showed a bipolar carrier‐injection/transporting capability caused by electron‐withdrawing anthracene and electron‐donating amino groups. Poly[N‐2‐ethylhexyl‐3,6‐phenothiazinylene vinylene‐alt‐2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylene vinylene], containing phenothiazinylene vinylene and dialkoxy phenylene vinylene moieties, showed excellent hole‐injection/transporting capability. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2502–2511, 2003     

High-Efficiency ZnCdSe/ZnSSe/ZnMgSSe Green Light-Emitting Diodes

Green light-emitting diodes (LEDs) were fabricated employing a ZnCdSe/ZnSSe triple quantum-well (TQW) active region surrounded by ZnMgSSe cladding layers grown on an n-type (100) GaAs substrate by molecular beam epitaxy (MBE). A 3.5 mW pure green emission was observed for the surface-emitting LED device at a peak wavelength of 513.3 nm (2.415 eV) with a spectral half-width of 11.7 nm (55 meV) under a 20 mA (4.6 V) direct current at room temperature (25°C). These correspond to an external quantum efficiency of 7.2%, a power conversion efficiency of 3.8%, a luminous current efficiency of 66 lm/A, and a luminous efficiency of 14 lm/W.     

Synthesis and characterization of indeno[1,2‐b]fluorene‐based white light‐emitting copolymer

An indenofluorene‐based copolymer containing blue‐, green‐, and red light‐emitting moieties was synthesized by Suzuki polymerization and examined for application in white organic light‐emitting diodes (WOLEDs). Tetraoctylindenofluorene (IF), 2,1,3‐benzothiadiazole (BT), and 4,7‐bis(2‐thienyl)‐2,1,3‐benzothiadiazole (DBT) derivatives were used as the blue‐, green‐, and red‐light emitting structures, respectively. The number‐average molecular weight of the polymer was determined to be 25,900 g/mol with a polydispersity index of 2.02. The polymer was thermally stable (T_d = ～398 °C) and quite soluble in common organic solvents, forming an optical‐quality film by spin casting. The EL characteristics were fine‐tuned from the single copolymer through incomplete fluorescence energy transfer by adjusting the composition of the red/green/blue units in the copolymer. The EL device using the indenofluorene‐based copolymer containing 0.01 mol % BT and 0.02 mol % DBT units ( PIF‐BT01‐DBT02 ) showed a maximum brightness of 4088 cd/m² at 8 V and a maximum current efficiency of 0.36 cd/A with Commission Internationale de L'Eclairage (CIE) coordinates of (0.34, 0.32). The EL emission of PIF‐BT01‐DBT02 was stable with respect to changes in voltage. The color emitted was dependent on the thickness of the active polymer layer; layer (～60 nm) too thin was unsuitable for realizing WOLED via energy transfer. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3467–3479, 2009     

Polyfluorenes minimally doped with 1,4‐bis(2‐thienyl‐2‐cyanovinyl)benzene chromophore: Their synthesis,characterization, and application to white‐light‐emitting materials

Copolyfluorenes ( PFR1 and PFR2 ), chemically doped with 0.1 and 0.025 mol % 2,5‐dihexyloxy‐1,4‐bis(2‐thienyl‐2‐cyanovinyl)benzene (MR chromophere) were synthesized by the Suzuki coupling reaction. The PFR s were used to fabricate white‐light‐emitting devices through incomplete energy transfer. Because of the low content of the MR chromophore, the optical, thermal, and electrochemical properties of the PFR s were almost identical to those of polyfluorene, except for their photoluminescent (PL) and electroluminescent (EL) properties. The copolymer films showed PL peaks at about 428 and 570 nm originating from fluorene segments and MR chromophores, respectively. Compared with the model compound ( MR ), the polymer chains extended the conjugation length of the MR chromophores and exhibited a 20–48 nm red‐shift in the emission band. In addition, the lower LUMO level of the MR (?3.27 eV) was expected to improve the electron injection. The EL devices [ITO/PEDOT:PSS/ PFR s/Ca (50 nm)/Al (100 nm)] showed a broad emission band, covering the entire visible region, with chromaticity coordinates of (0.36, 0.35) and (0.32, 0.30) for PFR1 and PFR2 devices, respectively. The emission color of the PFR2 device was very similar to that of a pure white light (0.33, 0.33); and the maximal brightness and current efficiency were 3011 cd/m² and 1.98 cd/A, respectively, which surpass those found for polyfluorene devices (1005 cd/m², 0.28 cd/A). A). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3703–3713, 2008     

LED大屏幕视频图象显示亮度校正的一种方法

在大屏幕视频显示的研究中,通常将侧重点放在显示驱动电路的优化上。本文从人眼的主观视觉理论出发,讨论了大屏幕视频图象显示与主观视觉之间的关系。并提出了一种很好的校正理论。经过实验检验,它能在图象列信息相同时,不管背景图象如何,均能使显示屏保持相同的亮度,使显示的视频图象的质量得以提高.     

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。