卟啉掺杂的MEH-PPV薄膜和氯仿溶液的光学性质(英文)

研究了不同质量浓度卟啉(TTP)掺杂的MEH-PPV的紫外吸收和荧光发射光谱。这种掺杂体系在膜中和氯仿溶液中的吸收光谱具有同样的行为,同时,在这两种情况下发现了MEH-PPV链的聚集,以及TTP在420nm的吸收随掺入量的增加而增加。但是,膜的发射光谱与氯仿溶液中的有所不同。因TTP的吸收带与MEH-PPV发射带的重叠,在膜和氯仿溶液中的高浓度掺杂体系中存在从MEH-PPV到TTP的Frster能量转移,但是在高TTP掺杂下的氯仿溶液中能量转移导致MEH-PPV发射峰的劈裂,而当溶液被稀释时,这种现象消失,表明此时能量给体和受体的距离扩大,这种能量转移的速率为1×108mg·mL-1·s-1。     

Poly[(BEHP-PPV)-co-(MEH-PPV)]:DCJTB为功能层LEC器件的能量传递

在有机发光器件中,掺杂染料分子是改变发光颜色,提高发光性能的有利手段.在掺杂体系中,主体材料向掺杂剂的能量传递是主要的激发态弛豫过程.在LEC器件中,利用掺杂手段改变发光颜色的方法报道很少.研究了以发射绿光(峰值550 nm)的共聚物Poly[(BEHP-PPV)-co-(MEH-PPV)]中掺杂DCJTB作为功能层的LEC器件的发光特性.器件的结构为ITO/Poly[(BEHP-PPV)-co-(MEH-PPV)]∶DCJTB+PEO+LiCF3SO3/Al.共聚物的光致发光光谱几乎覆盖了整个DCJTB吸收光谱的范围,满足能量传递的要求.通过光致发光与电致发光光谱的研究,发现掺杂后的薄膜不论是光致发光还是电致发光,都以DCJTB的发射为主,说明二者之间的确存在能量传递.     

基于量子点和MEH-PPV的白光发光二极管的研究

利用无机纳米材料与有机聚合物材料相结合的方法制备白光发光二极管器件, 研究了蓝光量子点QDs(B)掺杂聚[2-甲氧基-5-(2-乙基己氧基-1, 4-苯撑乙烯撑](MEH-PPV) 复合体系的发光特性及量子点QDs(B) 掺杂浓度(质量分数)不同对器件发光特性的影响. 制备了ITO/PEDOT:PSS/MEH-PPV:QDs(B)/LiF/Al 结构的电致发光器件, 测试了器件的电致发光光谱和电学、光学特性. 当QDs掺杂浓度为40%, 驱动电压为8 V时器件能得到较为理想的白光发射. 同时, 对比研究了非掺杂体系的发光特性, 制备了结构为ITO/PEDOT:PSS/MEH-PPV/QDs(B)/LiF/Al的器件, 掺杂体系相较于非掺杂体系, 器件的最大亮度增大, 启亮电压降低, 并分析了掺杂体系器件性能改善的原因.     

共轭聚合物中掺杂可溶性石墨烯对于OLED和OPV性能的影响

本文重点研究了不同浓度可溶性石墨烯(SPFGO)对于聚[2-甲氧基-5-(2-乙基己氧基)]对苯乙炔(MEH-PPV)/SPFGO复合薄膜的光致发光(PL)、 有机电致发光(OLED)和有机光伏(OPV)性能的影响. 研究发现, 在MEH-PPV中掺杂SPFGO之后, MEH-PPV/SPFGO复合薄膜的光致发光发生了非常强烈的猝灭, 意味着MEH-PPV和SPFGO之间发生了非常强烈的载流子传输. 当SPFGO的浓度较低的时候, 能够提高OLED的性能, 当SPFGO的浓度为0.2%时, OLED的性能达到最佳, 而此时的OPV性能基本没有改变. 当掺杂较高浓度的SPFGO 之后, OPV的性能有了明显的提升, 当浓度为15%时, OPV达到了最佳的性能, 而此时的OLED发生了非常强烈的猝灭. 通过实验数据可以看出, 当SPFGO较低浓度的时候, 起到增强载流子注入的作用, 提升OLED亮度的同时降低了开路电压. 而当SPFGO达到较高浓度时, SPFGO作为电子受体, 可以起到改善MEH-PPV/SPFGO 界面激子分裂和提高OPV性能的作用. 因此, 通过调节SPFGO浓度可以起到独立调控OLED性能和OPV性能的作用. 关键词： SPFGO OLED OPV     

掺杂DCJTB聚合物电化学池（LEC）的发光性质

通过在聚合物电化学池(LEC)发光器件的发光材料MEH-PPV中掺杂红光染料DCJTB,对LEC器件的发光性质进行研究。基于器件结构为ITO/MEH-PPV PEO LiCF3SO3/Al的薄膜LEC器件,其电致发光峰在570nm左右,通过在MEH-PPV与PEO的混合膜中掺杂不同比例的红光染料DCJTB,随着掺杂比例的增加,器件的发光峰由570nm向红光波段移动,通过控制DCJTB的掺杂比例制备了发光峰在570~650nm连续变化的LEC电致发光器件。对其分析认为从LEC主体发光聚合物MEH-PPV到染料DCJTB间发生了良好的能量传递。     

TBPe与MEH-PPV共掺杂的有机电致发光器件的优化研究

采用有机小分子TBPe(2,5,8,11-tetratertbutylperylene)以不同比例掺入MEH-PPV(poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene])作为发光层,研究了TBPe不同掺杂比例对器件性能的影响,进而对发光强度进行优化。对于所制备的ITO/PEDOT∶PSS/MEH-PPV/TBPe/Al有机电致发光器件,TBPe的最优蒸镀厚度为0.5 nm,其发光强度相对于标准器件提高了325%。ITO/PEDOT∶PSS/MEH-PPV∶TBPe/TBPe/Liq/Al有机电致发光器件的最优掺杂比例为MEH-PPV∶TBPe=100∶30(质量比),其发光亮度相比于未掺杂器件提高了44%。在上述器件的基础上增加Alq3层提高电子注入,分别制作了Liq和LiF作为修饰层的ITO/PEDOT∶PSS/MEH-PPV∶TBPe/TBPe/Alq3/Liq/Al和ITO/PEDOT∶PSS/MEH-PPV∶TBPe/TBPe/Alq3/LiF/Al多层器件,发光亮度分别达到4 162 cd/m2和4 701 cd/m2。所有器件的电致发光波长均为580 nm,为MEH-PPV的发光,TBPe的掺杂对MEH-PPV的发光起到了增强作用。     

掺磷光材料有机电致发光器件的能量传递

将高量子效率的磷光材料fac-tris-2-phenylpyridine iridium(III) (Ir(ppy)3)按不同的比例掺杂到具有载流子传输能力的主体材料poly(N-vinylcarbazole) (PVK)中作为发光层制备磷光电致发光器件。通过对器件发光机制的研究,发现光致发光过程中起主导作用的是Fo¨ster能量转移机制;而在电致发光过程中,器件的发光性能受Dexter能量转移和电荷陷获2种能量传递形式的影响。器件的I-V-L特性表明：Ir(ppy)3的掺杂比例为5%时,器件的光功率效率最大,能量转移最充分。     

PVK∶DBVP掺杂体系的能量转移及发光性质的研究

研究了不同比例的PVK与齐聚PPV衍生物DBVP掺杂体系的能量转移和发光特性.通过对PVK,DBVP及PVK:DBVP掺杂体系的UV-vis,PL和PLE光谱的研究,分析了PVK与DBVP之间的能量转移过程.利用PVK在体系中类似于溶剂的分散作用,制备了结构为ITO/PEDOT/PVK:DBVP/LiF/Al的电致发光器件,研究了掺杂体系的电致发光性能.结果表明,在掺杂体系的光致发光和电致发光中,PVK的发射被有效地抑制,PVK与DBVP之间发生了非常有效的能量转移,通过调节PVK与DBVP的比例,可以获得蓝色和绿色发光,同时可以改善器件的发光性能,当PVK与DBVP的重量比为1∶2时,器件的绿色发光效率达到1·06cd/A,此时发光亮度为52cd/m2.     

基于有机染料盐掺杂薄膜体系的能量转移及光致发光特性研究

利用稳态和时间分辨瞬态光谱研究了有机盐trans-4-［p-(N-ethyl-N-(hydroxyethyl)amino)phenylstyryl］-N-(hydroxyethyl)pyridinium iodide (ASPI)掺杂聚合物PVK(聚乙烯咔唑)薄膜体系的光致发光和能量转移特性. 在ASPI：PVK掺杂薄膜体系中,PVK的荧光强度与寿命随掺杂浓度的升高而降低,表明两者存在有效的Forster能量转移. 通过在相对低浓度的掺杂体系中加入适量高量子效率的Alq3作为能量转移过渡体,形成能量转移级 关键词： 有机染料盐 荧光光谱 荧光寿命 能量转移     

PVK:DBVP掺杂体系的能量转移及发光性质的研究

研究了不同比例的PVK与齐聚PPV衍生物DBVP掺杂体系的能量转移和发光特性.通过对PVK，DBVP及PVK: DBVP掺杂体系的UV-vis，PL和PLE光谱的研究，分析了PVK与DBVP之间的能量转移过程.利用PVK在体系中类似于溶剂的分散作用，制备了结构为ITO/PEDOT/PVK: DBVP/LiF/Al的电致发光器件，研究了掺杂体系的电致发光性能.结果表明，在掺杂体系的光致发光和电致发光中，PVK的发射被有效地抑制，PVK与DBVP之间发生了非常有效的能量转移，通过调节PVK与DBVP的比例，可以获得蓝色和绿色发光，同时可以改善器件的发光性能，当PVK与DBVP的重量比为1∶2时，器件的绿色发光效率达到1.06cd/A，此时发光亮度为52cd/m².     

The magnetic phase in 2-2-1-2 superconducting materials

Three related aspects of the magnetic phase diagram are presented here: the first deals with the disruption of the antiferromagnetic order in the electron rich phase obtained by Ce doping, the second concern the role of Bi planes as a sink-buffer of carriers, the third focuses the magnetization vs. temperature curves in a variety of different bilayer materials as seen by the muons and discusses the “anomalous” behaviour in relation to theoretical predictions and neutron scattering data.     

A Quantum Monte Carlo Study on Mixed-Spin Chains of 1／2-1／2-1-1 and 3／2-3／2-1-1

The ground-state and thermodynamic properties of quantum mixed-spin chains of 1/2-1/2-1-1 and 3/2-3/2-1-1 are investigated by a quantum Monte Carlo simulation with the loop-cluster algorithm. For 1/2-1/2-1-1 chain, we find it hastwo phases separated by an energy-gap vanishing point in the ground-state. For 3/2-3/2-1-1 chain,the numerical results show two energy-gap vanishing points isolated by different phases in its ground-state. Our calculations indicate that all these ground state phases can be understood by means of valence-bond-solid picture, and the thermodynamic behavior at finite temperatures is continuous as a function of parameter α=J2/J1.     

A Quantum Monte Carlo Study on Mixed-Spin Chains of 1/2-1/2-1-1 and 3/2-3/2 -1-1

The ground-state and thermodynamic properties of quantum mixed-spin chains of1/2-1/2-1-1and 3/2-3/2-1-1are investigated by a quantum Monte Carlo simulation with the loop-cluster algorithm. For 1/2-1/2-1-1 chain, we find it has two phases separated by an energy-gap vanishing point in the ground-state. For 3/2-3/2-1-1 chain, the numerical results show two energy-gap vanishing points isolated by different phases in its ground-state. Our calculations indicate that all these ground state phases can be understood by means of valence-bond-solid picture, and the thermodynamic behavior at finite temperatures is continuous as a function of parameterα=J2/J1.     

2-甲基-6-(2-甲苯基)-2-庚烯的波谱学研究

采用色谱法从蒲儿根花部位中分离得到2-甲基-6-(2-甲苯基)-2-庚烯,该化合物第一次以单体的形式得到,通过测定氢-氢相关谱(1H-1H COSY)、DEPT谱、异核单量子相关谱(HSQC)及异核多键相关谱(HMBC)等二维谱确定了该化合物的结构,并对该化合物的1H NMR和13C NMR谱进行了归属.     

An unusual synthesis of 3-(2-(arylamino)thiazol-4-yl)-2H-chromen-2-ones from ethyl 2-(chloromethyl)-2-hydroxy-2H-chromene-3-carboxylate via benzopyran ring opening

An unusual and unexpected synthesis of 3-(2-(arylamino)thiazol-4-yl)-2H-chromen-2-ones has been observed by the reaction of ethyl 2-(chloromethyl)-2-hydroxy-2H-chromene-3-carboxylate with various arylthioureas in ethanol under mild reaction conditions with excellent yields. The ambiguity in the structure of the obtained products has been solved by recording its single-crystal X-ray analysis. This protocol has been found to be a novel approach for the preparation of title compounds via benzopyran ring opening. A systematic plausible mechanism has been proposed for the formation of the product. Also, an efficient one-pot three-component method has been demonstrated for the formation of title compounds starting from salicylaldehyde.

     

Novel and convenient synthesis of 1-(pyridinylmethyl)-2-naphthols and 1-(pyridinylmethylene)-2-tetralones from 2-tetralones

The reaction of 2/4-pyridine carboxaldehyes with 2-tetralone analogs in the presence of catalytic amounts of Pd/C and trimethylsilyl chloride in DMF resulted in the formation of 1-(pyridin-2/4-ylmethyl)-2-naphthols in moderate to good yields as opposed to the expected 1-(pyridin-2/4-ylmethylene)-2-tetralones. 3-Pyridine carboxaldehyde, however, formed 1-(pyridin-3-ylmethylene)-2-tetralones with 2-tetralone analogs under similar conditions. When representative reactions were repeated in the presence of anhydrous HCl gas in acetic acid, including one with 3-pyridine carboxaldehyde, 1-(pyridinylmethyl)-2-naphthols were the only products obtained with significantly improved yields. A possible mechanism explaining these results is discussed.     

Identification ofμ +-sites in the 1-2-3 compoundin the 1-2-3 compound

Possibleμ ⁺ sites have been identified by a comparison of measured spontaneous internal fields in YBa₂Cu₃O_6+δ and REBa₂Cu₃O_7−δ and of measured second moments and width of transverse field powder spectra with the corresponding calculated quantities. In the YBa₂Cu₃O₇ system only one possibleμ ⁺ site emerges at a distance of ∼1.05 A from a chain oxygen O(4) at the position (0.15(1), 0.44(1), 0.071(1)). In the system YBa₂Cu₃O₆ the only possibleμ ⁺ sites are near to an oxygen O(1) with z/c=0.133 and the same distance as above. The analysis leads also to improved valuesμ _Ho = 2.2(1)μ _B andμ _Cu = 0.67(4)μ _B and to a determination of the latters direction:μ _Cu ‖〈110〉.     

Mössbauer study of tin-doped 1-2-3 and 2-1-4 highT c superconductors

Samples of YBa₂(Cu_0.85Sn_0.15)₃O_7–y (1-2-3), La₂(Cu_0.95Sn_0.05)O4_4–x, and La_1.85Ba_0.15(Cu_0.95Sn_0.05)O_4–x (2-1-4), with different oxygen stoichiometry, have been studied by Mössbauer spectroscopy. These measurements reveal the existence of two inequivalent sites for Sn in the (1-2-3) compounds. The (1-2-3) spectra display two quadrupole doublets which we associate with Sn in Cu(1) and Cu(2) sites, respectively. La compounds show a single quadrupole doublet.