Substantial photo-response of InGaN p-i-n homojunction solar cells

InGaN p-i-n homojunction structures were grown by metal-organic chemical vapor deposition, and solar cells with different p-contact schemes were fabricated. X-ray diffraction measurements demonstrated that the epitaxial layers have a high crystalline quality. Solar cells with semitransparent p-contact exhibited a fill factor (FF) of 69.4%, an open-circuit voltage (V-oc) of 2.24 V and an external quantum efficiency (EQE) of 41.0%. On the other hand, devices with grid p-contact showed the corresponding values of 57.6%, 2.36 V, 47.9% and a higher power density. These results indicate that significant photo-responses can be achieved in InGaN p-i-n solar cells.

Improved diphasic nc-si/a-si : H I-layer materials using PECVD

Two series of films has been prepared by using a new regime of plasma enhanced chemical vapor deposition (PECVD) in the region adjacent to the phase transition from amorphous to crystalline state. The photoelectronic properties of the films have been investigated as a function of crystalline fraction. In comparison with typical a-Si:H, these diphasic films with a crystalline fraction less than 0.3 show a similar optical absorption coefficient, higher mobility life-time product ( LT) and higher stability upon light soaking. By using the diphasic nc-Si/a-Si films as the intrinsic layer, a p-i-n junction solar cell has been prepared with an initial efficiency of 9. 10 % and a stabilized efficiency of 8.56 % (AM 1.5, 100 mW/cm(2)).

咪唑衍生物为配体的铜(I)配合物合成及光物理性质

本论文以咪唑衍生物为配体,合成了新型Cu(I)中性配合物和对应的离子型配合物，考察了它们的光物理和电化学性质。具体工作如下： 设计与合成了分别以2-(2'-吡啶基)苯并咪唑(Hpbm)和2-(2'-喹啉基)苯并咪唑(Hqbm)为配体的Cu(I)中性配合物和四氟硼酸根为抗衡离子的离子型配合物。配合物的晶体结构表明中心铜离子均为扭曲的四面体配位构型，中性配合物的咪唑环中的键长趋于平均化。所有配合物在20wt%浓度的PMMA薄膜中的最大发射处于518.5-597.5nm之间，发光效率为0.097-0.249, 磷光寿命为11.7-25.9µs。中性配合物与对应的离子型配合物相比，其紫外可见吸收光谱发生红移，光致发光光谱发生蓝移。 以2, 2'-联苯并咪唑为配体(H2dbm)，设计和合成了双核和单核Cu(I)配合物，其中双核配合物Cu2(dbm)(PPh3)4在二氯甲烷溶液和PMMA (20 wt%)薄膜中均表现为蓝光发射，在20wt%浓度的PMMA薄膜中的最大发射为448.5和475.5nm。单核离子型配合物[Cu(Hdbm)(PPh3)]2[BF4]在20wt%浓度的PMMA薄膜中的最大发射分别为511，发光效率分别为0.150, 磷光寿命分别为12.0。

I：端羟基液体聚丁二烯的氯化 II：氯化端羟基液体聚丁二烯的固化

合成了一系列氯含量不同的氯化丁羟（氯含量为5％～68％）。利用红外光谱、核磁共振观察了氯含量不同的氯化丁羟的双键变化。通过氯含量－5反应时间的关系及上述观察结果表明；丁羟在四氯化碳中进行氯化，首先进行加成反应，待双键饱和后，进行取代反应。用红外光谱观察了丁羟在氯化反应中三种微观结构的变化，观察了氯化高顺式聚丁二烯的双键变化，对氯化丁羟的赤苏异构体的碳－氯键红外光密度比值，进行了分析。这些观察和分析说明；丁羟在四氯化碳中氯化，存在着顺－反异构化反应。较详细地研究了影响交联反应的主要因素，利用低聚物的特点，通过数均分子量和粘度表征了交联反应程度。从而观察到，交联反应伴随着氯化反应之中，交联程度随着反应液中羟浓度的提高，随着反应时间的延长而增大。在一定反应液浓度下交联程度可以减小到很低程度，得到完全可溶的氯化丁羟。反应温度对交联反应在20～76℃范围无显著影响。提出了以氯乙醇为调节剂合成液体氯化丁羟的方法。实验结果说明，氯乙醇比文献中得到的乙醇在抑制交联反应，提高氯含量方面效果更好。氯化丁羟的羟值分析结果表明，丁羟的羟值在氯化反应中没有损失。这对氯化丁羟作为遥瓜型低聚物应用，在进行固化反应时，是非常重要的。随着溶剂介电常数的提高，出现凝胶的极限浓度也提高。根据这一实验和上述各项实验结果，基于烯类化合物氯化反应的一些基础研究工作。我们认为，在丁羟的氯化反应中，存在着两种反应机理；离子机理的加成，导致可溶氯化产物，自由基机理除加成外，导致交联，顺－反异构化反应。II 氯化丁羟与TDI的反应为二级反应。DBTDL（二月桂酸二丁基锡）对本固化反应有明显的催化效果。在100 ℃，以DBTDL为催化剂的固化反应中，氯化丁羟与TDI的反应速度常数为11.9 * 10~(-3)（升／克分子·秒），这个反应活化能为5.5千卡／克分子。合成了一系列的氯化丁羟聚氨酯。红外光谱测试结果表明，NH基分为两个红外吸收峰；3440 cm~(-1), 3310 cm~(-1)。高波频峰的为游离的NH基，低波频峰为缔合的NH基，其缔合度为88％。同时，表征了氯化丁羟聚氨酯的主要红外光谱吸收峰。研究了氯化丁羟聚氨酯的形态结构。透射电子微显镜示出氯化丁羟聚氨酯的微相分离区域结构，其硬段区域结构的尺寸大约趋于在0.7～1.6μ范围内（硬段含量30％）。差热分析和示差扫描量热分析结果一致表明，氯化丁羟聚氨酯在60 ℃-90 ℃范围内有一宽而弱的吸热转变区，在115 ℃左右有一吸热峰，它们归因于硬段区域结构的热转变。宽角X光衍射实验没有观察到明显的结晶吸收峰的存在。这个实验结果主要与氯化丁羟聚氨酯的无规、侧基及不对称的结构特点有关。初步实验结果显示出，氯化丁羟聚氨酯具有优异的粘结性能，其抗剪强度约是丁羟聚氨酯的六倍。通过氧化锌的作用，可以提高氯化丁羟聚氨酯的抗张强度。因为粘结强度是水轮机耐磨耐汽蚀涂层研制中比较关键的因素，所以，这个实验结果是很有意义的。

I 蓖麻油聚氨酯/聚甲基丙烯酸甲酯AB交联聚合物的研究 II 双阳原油热处理中加入降凝剂的研究

用蓖麻油与TDI反应生成端异氰酸酯基预聚物，再与HEA反应，生成端乙烯基预聚物，以不同比例的MMA与端乙烯基预聚物共聚交联，得到一组组成和交联密度各不相同的ABCP样品；为了分别观察组成和交联密度对材料性能的影响，在交联共聚过程中，以二乙烯基苯作交联点调节剂 ，得到固定组成，交联密度变化和固定交联密度组成变化的两组样品；此外，在固化过程中加入不同含量的丙烯酸（<10%），得到另一组样品，以观察氢键对该体系的影响。反应过程中用化学分析、NMR、IR及平衡溶胀等方法测定反应程度、分子量及交联网的交联密度；同时用动态粘弹谱仪和介电损耗仪测定样品的动态力学性能，转变与松弛及相容性；用材料试验机测试样品的力学性能；通过透射电子显微镜观察材料的形态结构。结果表明：copu/PMMA ABCP是个半相容体系，随硬段含量的增加和交联密度的减小相容性变差。形态结构呈不规则形状，相区尺寸由几A变至几百A，材料的力学性能和阻尼性能明显优子构成它们的均聚物。材料的阻尼值主要受交联密度的影响，玻璃化转变温度则主要受组成控制。氢键对该体系的形态结构有明显影响，丙烯酸含量为7.5%时相容性最差，5%和10%时最好。以双阳昌10号井原油为研究对象选用EVA作原料，以马来酸酐接枝改性，合成ET-6降凝剂。采取在热处理中加入降凝剂的综合处理方法，考察了降凝剂合成的最佳反应条件和降凝剂用量及热处理温度对原油结晶状态及流动性的影响。结果表明，热处理中加入ET-6降凝剂可使蜡的结晶形态发生明显变化，降凝剂用量仅100-500 ppm即可使双阳原油的凝固点由原来的30-31 ℃降至7-9 ℃，原油的低温流动性大为改观。

Identified particle production, azimuthal anisotropy, and interferometry measurements in Au plus Au collisions at root s(NN)=9.2 GeV

We present the first measurements of identified hadron production, azimuthal anisotropy, and pion interferometry from Au + Au collisions below the nominal injection energy at the BNL Relativistic Heavy-Ion Collider (RHIC) facility. The data were collected using the large acceptance solenoidal tracker at RHIC (STAR) detector at root s(NN) = 9.2 GeV from a test run of the collider in the year 2008. Midrapidity results on multiplicity density dN/dy in rapidity y, average transverse momentum < p(T)>, particle ratios, elliptic flow, and Hanbury-Brown-Twiss (HBT) radii are consistent with the corresponding results at similar root s(NN) from fixed-target experiments. Directed flow measurements are presented for both midrapidity and forward-rapidity regions. Furthermore the collision centrality dependence of identified particle dN/dy, < p(T)>, and particle ratios are discussed. These results also demonstrate that the capabilities of the STAR detector, although optimized for root s(NN) = 200 GeV, are suitable for the proposed QCD critical-point search and exploration of the QCD phase diagram at RHIC.

Red-Light-Emitting Iridium Complexes with Hole-Transporting 9-Arylcarbazole Moieties for Electrophosphorescence Efficiency/ Color Purity Trade-off Optimization

The synthesis, structures, photophysics, electrochemistry and electrophosphorescent properties of new red phosphorescent cyclometalated iridium(III) isoquinoline complexes, bearing 9-arylcarbazolyl chromophores, are reported. The functional properties of these red phosphors correlate well with the results of density functional theory calculations. The highest occupied molecular orbital levels of these complexes are raised by the integration of a carbazole unit to the iridium isoquinoline core so that the hole-transporting ability is improved in the resulting complexes relative to those with I-phenylisoquinoline ligands. All of the complexes are highly thermally stable and emit an intense red light at room temperature with relatively short lifetimes that are beneficial for highly efficient organic light-emitting diodes (OLEDs).

Novel Re(I) dendrimers: synthesis, characterization and theoretical studies

Four novel diimine rhenium(I) carbonyl complexes with the formula [Re(CO)(3)(L) Br], where L = 2-(4-(9H-carbazol-9-yl) phenyl)-1H-imidazo[4,5-f][1,10] phenanthroline (P1), 2-(4-(3,6-di-tert-butyl-9H-carbazol-9-yl) phenyl)-1H-imidazo-[4,5-f][1,10] phenanthroline (P2), 2-(4-(6-(9H-carbazol-9-yl)-9H-3,9'-bicarbazol-9-yl) phenyl)-1H-imidazo[4,5-f][1,10] phenanthroline (D1), and 2-(4-(3', 6'-di-tert-butyl-6-(3,6-di-tert-butyl-9H-carbazol-9-yl)-9H-3,9'-bicarbazol-9-yl) phenyl)-1H-imidazo[4,5-f][1,10] phenanthroline (D2), have been successfully synthesized and fully characterized by (HNMR)-H-1, IR, and UV-Vis, etc. The luminescence quantum yields (LQYs) of the parent Re(I) complexes P1 and P2 are 0.13 and 0.16, respectively, which are much higher than the previously reported Re(I) dendrimers. The HOMOs and the LUMOs of P1 and P2 are calculated to be mainly composed of [d(Re) + pi(CO + Br)] and pi*(L) orbital, respectively.

Novel heteroleptic Cu-I complexes with tunable emission color for efficient phosphorescent light-emitting diodes

A series of orange-red to red phosphorescent heteroleptic Cu-I complexes (the first ligand: 2,2 '-biquinoline (bq), 4,4 '-diphenyl2,2 '-biquinoline (dpbq) or 3,3 '-methylen-4,4 '-diphenyl-2,2 '-biquinoline (mdpbq); the second ligand: triphenylphosphine or bis[2-(diphenylphosphino)phenyl]ether (DPEphos)) have been synthesized and fully characterized. With highly rigid bulky biquinoline-type ligands, complexes [Cu(mdpbq)(PPh3)(2)](BF4) and [Cu(mdpbq)(DPEphos)](BF4) emit efficiently in 20 wt % PMMA films with photoluminescence quantum yield of 0.56 and 0.43 and emission maximum of 606 nm and 617 nm, respectively. By doping these complexes in poly(vinyl carbazole) (PVK) or N-(4-(carbazol-9-yl)phenyl)-3,6-bis(carbazol-9-yl) carbazole (TCCz), phosphorescent organic light-emitting diodes (OLEDs) were fabricated with various device structures. The complex [Cu(mdpbq)(DPEphos)](BF4) exhibits the best device performance. With the device structure of ITO/PEDOT/ TCCz:[Cu(mdpbq)(DPEphos)](BF4) (15 wt %)/TPBI/LiF/Al (III), a current efficiency up to 6.4 cd A(-1) with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.61, 0.39) has been realized. To our best knowledge, this is the first report of efficient mononuclear Cu complexes with red emission.

Highly efficient electroluminescence from green-light-emitting electrochemical cells based on Cu-I complexes

The complexes [Cu(dnpb)(DPEphos)](+)(X-) (dnpb and DPEphos are 2,9-di-n-butyl-1,10-phenanthroline and bis[2-(diphenyl-phosphino)phenyl]ether, respectively, and X- is BF4-, ClO4-, or PF6-) can form high quality films with photoluminescence quantum yields of up to 71 +/- 7%. Their electroluminescent properties are studied using the device-structure indium tin oxide (ITO)/complex/metal cathiode. The devices emit green light efficiently, with an emission maximum of 523 nm, and work in the mode of light-emitting electrochemical cells. The response time of the devices greatly depends on the driving voltage, the counterions, and the thickness of the complex film. After pre-biasing at 25 V for 40 s, the devices turn on instantly, with a turn-on voltage of ca. 2.9 V. A current efficiency of 56 cd A(-1) and an external quantum efficiency of 16% are realised with Al as the cathode. Using a low-work-function metal as the cathode can significantly enhance the brightness of the device almost without affecting the turn-on voltage and current efficiency. With a Ca cathode, a brightness of 150 cd m(-2) at 6 V and 4100 cd m(-2) at 25 V is demonstrated. The electroluminescent performance of these types of complexes is among the best so far for transition metal complexes with counterions.

Synthesis, crystal structure, and photoluminescent property of a novel heterobimetallic Zn(II)-Ag(I) cyano-bridged coordination polymer incorporating,a pentameric unit [Ag(CN)(2-)](5) assembled by argentophilic interaction

A new photoluminescent heterobimetallic Zn(II)-Ag(I) cyano-bridged coordination polymer, [Ag5Zn2(tren)(2)(CN)(9)] (tren = tris(2-aminoethyl)amine) (1), has been synthesized and structurally characterized. It features rare linear pentameric unit of dicyanoargentate(I) ions assembled by d(10)-d(10) interaction as building blocks. Solid state emission spectrum of I shows strong ultraviolet luminescence with emission peak in the range of 376 nm.

Preparation, patterning and luminescent properties of oxyapatite La-9.33(SiO6)(4)O-2 : A (A = Eu3+, Tb3+, Ce3+) phosphor films by sol-gel soft lithography

Silicate oxyapatite La-9.33 (SiO6)(4)O-2:A (A = Eu3+, Tb3+ and/or Ce3+) phosphor films and their patterning were fabricated by a sol-gel process combined with soft lithography. X-ray diffraction (XRD), Fourier transform infrared spectroscopy, atomic force microscopy, optical microscopy and photoluminescence spectra, as well as lifetimes, were used to characterize the resulting films. The results of XRD indicated that the films began to crystallize at 800degreesC and the crystallinity increased with the increase in annealing temperatures. Transparent nonpatterned phosphor films were uniform and crack-free, which mainly consisted of rodlike grains with a size between 150 and 210 nm. Patterned thin films with different bandwidths (20, 50 mum) were obtained by the micromoulding in capillaries technique. The doped rare earth ions (Eu3+, Tb3+ and Ce3+) showed their characteristic emission in crystalline La-9.33(SiO6)(4)O-2 phosphor films, i.e. Eu3+ D-5(0)-F-7(J) (J = 0, 1, 2, 3, 4), Tb3+ D-5(3,4)-F-7(J) (J = 3, 4, 5, 6) and Ce3+ 5d (D-2)-4f (F-2(2/5), F-2(2/7)) emissions, respectively. Both the lifetimes and PL intensity of the Eu3+, Tb3+ ions increased with increasing annealing temperature from 800 to 1100 degreesC, and the optimum concentrations for Eu3+, Tb3+ were determined to be 9 and 7 mol% of La3+ in La-9.33(SiO6)(4)O-2 films, respectively. An energy transfer from Ce3+ to Tb3+ was observed in the La-9.33(SiO6)(4)O-2:Ce, Tb phosphor films, and the energy transfer efficiency was estimated as a function of Tb3+ concentration.