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1.
富勒烯掺杂NPB空穴传输层的有机电致发光器件   总被引:1,自引:0,他引:1       下载免费PDF全文
牛连斌  关云霞 《物理学报》2009,58(7):4931-4935
报道了不同掺杂浓度NPB:C60(富勒烯)作为空穴传输层对有机电致发光器件性能的影响.采用真空热蒸镀方法,制作了ITO/ NPB:C60x % )/Alq3/LiF/Mg:Ag结构的四种有机电致发光器件.当NPB:C60的掺杂浓度是15%时,器件的启亮电压是4 V,最大亮度是11000 cd/m2.然而,当NPB:C60的掺杂浓度是20%时,器件的最大亮度降  相似文献   

2.
本文发现CoB16-团簇由两个对称、上下错位相连的B8环和位于中心的Co原子组成,它代表了金属掺杂硼纳米管结构的潜在雏形,这一发现为设计一维金属-硼纳米结构提供了机会. 本文报道了CoB16-新的实验光电子能谱,并采用量子化学方法对其电子结构和化学成键特性进行了详细的电子结构分析,为进一步了解金属掺杂硼纳米管结构的化学键和稳定性提供了深入的见解. 有趣的是,发现该类体系的中心Co原子具有异常低的氧化态,即负一价钴(-1). 因此中性CoB16分子可以被视为配体到金属的电荷转移化合物(Co-@BB16+). 研究表明,掺杂金属和硼管之间的相互作用来源于共价和静电作用的相互协调,硼元素低的电负性使得硼团簇成为形成各种低价态化合物的重要化学配体.  相似文献   

3.
利用具有同步辐射源的反射式飞行时间质谱仪,研究甲基环己烷的真空紫外光电离和光解离. 观测到母体离子C7H14+和碎片离子C7H13+,C6H11+,C6H10+,C5H10+,C5H9+,C4H8+,C4H7+和C3H5+的光电离效率曲线. 测定甲基环己烷的电离能为9.80±0.03 eV,通过光电离效率曲线确定其碎片离子的出现势. 在B3LYP/6-31G(d)水平上对过渡态、中间体和产物离子的优化结构进行表征,并使用G3B3方法计算其能量. 提出主要碎片离子的形成通道. 分子内氢迁移和碳开环是甲基环己烷裂解途径中最重要的过程.  相似文献   

4.
张泳 《化学物理学报》2020,33(1):101-106
目前在天文环境中探测到了C60、C70、C60+,极大地刺激了对星周包层中富勒烯衍生物的研究. 原行星状星云是富勒烯在天文环境下的可能形成源,其红外光谱中具有丰富的、还未能认证的特征谱带,其中在21 μm处的一条谱带尤为神秘. 当富勒烯被氢化,分子的对称性被破坏,能够激活新的红外振动谱,这有可能部分解释天文光谱中的红外谱带. 本文对氢化富勒烯的理论振动谱进行研究,考查了氢化富勒烯能否作为21 μm辐射的载体,详细讨论了各种支持和反对的证据,并且推测了可能贡献21 μm特征的氢化富勒烯的氢化程度.  相似文献   

5.
利用等温滴定量热仪、圆二色谱和荧光光谱,研究和分析了人工合成的DNA单链序列d(T6C6T6C6T6C6T6)与Hg2+和Ag+相互作用的折叠过程. 在改变离子添加顺序的情况下,尽管热力学数据显示两种情况下都能通过两种不同反应路径得到一种相对稳定的发夹结构,但等温滴定量热仪数据却显示最终产物形成的机理截然不同.当先加入Hg2+时,发夹结构首先通过T-Hg-T碱基对形成然后C-Ag-C碱基对得到进一步稳定. 然而当先加入Ag+时,通过圆二色谱和荧光分析确认了一种不常见的金属碱基对T-Ag-C取代了经典的C-Ag-C碱基对.  相似文献   

6.
本文介绍了真空紫外光电离质谱结合理论计算研究环戊酮单分子的光电离解离过程. 在9.0∽15.5 eV能量范围内,测量了环戊酮离子及其碎片离子的光电离效率曲线. 通过光电离效率曲线,将环戊酮分子的电离能确定为9.23±0.03 eV,并确认碎片离子为:C5H7O+,C4H5O+,C4H8+,C3H3O+,C4H6+,C2H4O+,C3H6+,C3H5+,C3H4+,C3H3+,C2H5+, C2H4+. 利用量子化学计算方法,在ωB97X-D/6-31+G(d,p)理论水平基础上,提出了C5H8O+的解离机制. 通过对环戊酮解离路径的分析,发现开环和氢迁移过程为环戊酮离子解离的主要路径.  相似文献   

7.
最近Anst?ter, et al. 发表了对阴离子-π复合物(I-·C6F6)的第一个定量谱学测量[J. Am. Chem. Soc. 141, 6132 (2019)],认为成键作用中相关作用占41%,静电作用占23%,得出相关作用占主导的结论. 本研究表明,该文献的“静电作用”中混入了Pauli排斥作用,后者在数值上抵消了前者的作用. 在复合物I-·C6F6中,发现静电作用是相关作用的两倍多,因而阴离子-π复合物中仍应是静电作用占主导.  相似文献   

8.
利用脉冲激光溅射-超声分子束载带方法制备气相硼羰基络合物正离子. 采用红外光解离光谱研究了B(CO)3+、B(CO)4+ 和B2(CO)4+的振动光谱. 研究结果表明B(CO)3+具有非常强的B-CO键,无法直接获得其红外光解离光谱. 对B(CO)4+的光解离光谱研究表明该离子是一个B(CO)3+和CO之间弱相互作用络合物. 其中B(CO)3+核具有平面D3h对称性结构,中心硼具有稳定的8电子组态. B2(CO)4+具有平面的D2h对称性结构,其中的B-B键包含一个σ键和半个π键. 自然轨道能量分解分析(EDA-NOCV)表明在B(CO)3+和B2(CO)4+中的B-CO成键作用中OC→B(σ)要比B→CO(π)反馈作用强.  相似文献   

9.
姜宗福  杨丽佳 《物理学报》1996,45(8):1287-1291
采用规范不变分子轨道理论给出磁化率的计算公式,对C60,C70,C76,C78,C82和C84等π电子的磁化率进行了计算.计算结果显示出富勒烯(Fullerene)有较大的抗磁磁化率,并且具有椭球形状的富勒烯,如C70,C76等的抗磁磁化率表现出明显的各向异性特性.  相似文献   

10.
 利用高温熔融法制备了不同浓度的Tb3+掺杂硅酸盐玻璃,并分别测量了紫外和X射线激发时的发射光谱。光谱结果表明,不同浓度Tb3+掺杂硅酸盐玻璃在紫外和X射线激发时发光行为具有相似的浓度依赖关系:低浓度Tb4O7掺杂时主要以蓝光(5D37FJ)发射为主,而高浓度掺杂时以绿光(5D47FJ)发射为主。Tb3+发光强度与掺杂浓度的关系分析表明,5D3的浓度猝灭是电偶极-电偶极相互作用引起的, 而5D4的浓度猝灭是交换相互作用引起的。  相似文献   

11.
Ammonia adsorption on the external surface of C30B15N15 heterofullerene was studied using density functional calculations. Three models of the ammonia-attached C30B15N15 together with the perfect model were optimized at the B3LYP/6-31G? level. The optimization process reveals that dramatic influences occurred for the geometrical structure of C30B15N15 after ammonia adsorption; the B atom relaxes outwardly and consequently the heterofullerene distorts from the spherical form in the adsorption sites. The chemical shielding (CS) tensors and nuclear quadrupole coupling constants of B and N nuclei were calculated at the B3LYP/6-311G** level. Our calculations reveal that the B atom is chemically bonded to NH3 molecule. The B atom in the NH3-attached form has the largest chemical shielding isotropic (CSI) value among the other boron nuclei. The CQ parameters of B nuclei at the interaction sites are significantly decreased after ammonia adsorption.  相似文献   

12.
We have investigated the structural and electronic configurations of the H@X-doped C60 fullerene (X = B, Si, P, O, S) as the novel materials for quantum bit (qubit) application by using density functional theory with the generalized-gradient approximation. Our results show that incorporated hydrogen atom exhibits significantly different interaction strengths and the calculated binding energies follow the hierarchy H@C59O < H@C59Si < H@C60 < H@C59B < H@C59S < H@C59P. In the considered complexes the binding energy is negative and the incorporated 1H atom resides at the center of heterofullerene nanocages. The obtained results also reveal that for the H@C59P complex the binding energy is four times higher than that of the traditional H@C60 fullerene, thus the H@C59P seems to be a promising material for the solid state quantum computers. Furthermore, the electronic and magnetic structures of the considered complexes at their ground state are discussed within the context.  相似文献   

13.
In the present study, the adsorption behaviour of methanol (CH3OH) and ethanol (C2H5OH) molecules over heterofullerene C59B surface is studied by density functional theory calculations. This heterofullerene is obtained from C60 by substituting a carbon atom with a boron atom and relaxing self-consistently the structure to the local minimum. The adsorption of CH3OH and C2H5OH on the C59B is exothermic and the relaxed geometries are stable. The CH3OH and C2H5OH adsorption can also induce a change in the highest occupied molecular orbital and the lowest unoccupied molecular orbital energy gap of the nanocage. The dehydrogenation pathways of CH3OH and C2H5OH via O–H and C–H bonds scission are also examined. The results indicate that O–H bond scission is the most favourable pathway on the C59B surface.  相似文献   

14.
ABSTRACT

Hydrogen storage reactions on Ni ? C59X(X = B, N) heterofullerene are investigated by using the state-of-the-art density functional theory calculations. The Ni atom prefers to bind at the bridge site between two hexagonal rings, and can bind up to five hydrogen molecules with average adsorption energies of (?0.94, ?0.48, ?0.33, ?0.25 and ?0.20 eV) per hydrogen molecule for Ni ? C59B, while (?1.20, ?0.60, ?0.41, ?0.28 and ?0.23 eV) per hydrogen molecule for Ni ? C59N. With no metal clustering, the system gravimetric capacities are expected to be as large as 10.87 and 10.85 wt % for 5H2NiC59B?and 5H2NiC59N, respectively. While the desorption activation barriers of the complexes 1H2 + C59X?(X = B, N)?are outside the Department of Energy domain (?0.2 to ?0.6 eV), the desorption activation barriers of the complexes nH2 + C59X(X = B, N)(n = 2 ? 5) are inside this domain. The hydrogen storage of the irreversible 1H2 + NiC59X?(X = B, N) and reversible 2H2 + NiC59X?(X = B, N) interactions is characterised in terms of density of states and projected densities of states, pairwise and non-pairwise additivity, infrared, Raman, electrophilicity and molecular electrostatic potentials.  相似文献   

15.
Single P-doped heterofullerene C59P is investigated via semiempirical and density functional theory calculations. Static geometric optimization shows that structural deformation occurs in the vicinity of the dopant atom and gives rise to P-C bonds significantly larger than the ordinary C-C bonds of the fullerene cage. The HOMO and LUMO lie in the middle of the energy gap of the undoped system. Unlike the HOMOS and LUMOs of C59Si and C59N, which are strongly localized on the dopant site, the C59P HOMO and LUMO are weakly localized on the environment of the dopant site. To a first good approximation the dopant P can be considered in the 1 + charge state.  相似文献   

16.
We studied the structural, electronic, and magnetic properties of C59Ir, C58Ir2, and C69Ir heterofullerenes by employing density functional theory and the generalized gradient approximation. There are six distinct isomers of C58Ir2 with high probability to form stable structures. The most stable structure of the C69Ir heterofullerene was investigated by comparing the iridium binding energies at the different atomic sites on the D5h C70 cage. There is a strong hybridization between the atomic orbitals of the iridium and those of the carbon atoms, leading to the spin quenching of the iridium atoms in the most stable C58Ir2 heterofullerene.  相似文献   

17.
Adsorption of NH3 and NO2 molecules on the external surface of C48B6N6 heterofullerene is investigated using DFT method. Attachment of NH3 and NO2 on C48B6N6 heterofullerenes are compared with the bare C48B6N6 model optimized at the B3LYP/6-31G? level. The high surface binding energies indicates that ammonia undergoes chemical adsorption and could be compatible with the long recovery time but C48B6N6 should be good NO2 sensors with quick response as well as short recovery time. Total (TDOS) and partial (PDOS) density of state calculations is also considered to elucidate the difference in the NH3 and NO2 gas detection mechanism of C48B6N6. The overlap population density of state (OPDOS) indicated that the chemical adsorption is due to the overlap of atomic orbitals below the Fermi level. The calculated results suggest that the C48B6N6 heterofullerene is a suitable sensor material for NO2 and is an ideal material for elimination and filtering of ammonia.  相似文献   

18.
Using B3LYP/6-31G* density functional level of theory, the structural and optical properties of the C60 and M@C59X cages have been investigated. Results indicate that the charge on C atoms and band gap of C60 cage are changed dramatically with the substitution of one B or N atom at one of the C sites and the Li and Na atom encapsulations in the C60 cage. The Mulliken analyses show that the charge is transferred completely between the alkali atoms and the C59X cage. The substitutional and encapsulation doping (SED) reduce the optical gaps of the C60 cage. Also, the oscillator strengths of the absorption peaks are dependent on dopant types.  相似文献   

19.
We performed density functional theory calculations to investigate the possibility of formation of endohedrally H@(BN)n–fullerene (n: 24, 36, 60) and H@C60 complexes for potential applications in solid-state quantum-computers. Spin-polarized approach within the generalized gradient approximation with the Perdew–Burke–Ernzerhof functional was used for the total energies and structural relaxation calculations. The calculated binding energies show that H atom being incorporated into B60N60 nanocage can form most stable complexes while the B24N24 and C60 nanocages might form unstable complex with positive binding energy. We have also examined the penetration of an H atom into the respective nanocages and the calculated barrier energies indicate that the H atom prefers to penetrate into the B24N24 and B60N60 nanocages with barrier energy of about 0.47 eV (10.84 kcal/mol). Furthermore the binding characteristic is rationalized by analyzing the electronic structures. Our findings reveal that the B60N60 nanocage has fascinating potential application in future solid-state quantum-computers.  相似文献   

20.
Design of spin labels inside for possible molecular spintronics, which contains of 1D spin chain filling single-walled carbon nanotube (SWCNT) with magnetic endohedral fullerenes of (14N@C60)2, 14N@C60 and C59N has been proposed. Electronic structure and magnetic properties of (14N@C60)2-SWCNT, 14N@C60-SWCNT, 14N@C60 and C59N were characterized. Geometrical effect of (14N@C60)2, 14N@C60 and C59N within SWCNT on chemical shift of 13C, principal g-tensor, A-tensor in hfc of nitrogen atom and excited state transition was investigated by ab-initio density functional theory. The magnetic properties would be originated in the spin density distribution with π-electron interaction between encapsulated fullerenes and inner surface on SWCNT and extent of charge transfer.  相似文献   

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