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新一代有机电致发光材料突破激子统计 被引量:6
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作者 杨兵 马於光 《中国科学:化学》 CAS CSCD 北大核心 2013年第11期1457-1467,共11页
激子(或自旋)统计是基本的物理原理,决定有机半导体器件中形成单线态与三线态激子的比例(1:3).近年来,基于新原理(三线态反系间窜越、延迟荧光)的OLED材料引起广泛关注.该类材料在理论方面重新催热了关于自旋统计的探讨,在应用方面有望... 激子(或自旋)统计是基本的物理原理,决定有机半导体器件中形成单线态与三线态激子的比例(1:3).近年来,基于新原理(三线态反系间窜越、延迟荧光)的OLED材料引起广泛关注.该类材料在理论方面重新催热了关于自旋统计的探讨,在应用方面有望发展成为低成本、高性能的新一代OLED材料,在国内相关领域得到重视,多个研究机构已布局开展相关研究.从目前的发展情况看,该类材料的发光机制、原理以及进一步材料设计思路还有待探讨和明确.鉴于此,本文综述了激子统计研究进展,分析了多种提高激子利用效率的途径,提出本课题组提高激子利用率的"热激子过程"新思路及杂化局域-电荷转移(HLCT)态材料设计原理,器件实现接近100%的激子利用效率. 展开更多
关键词 有机电致发光 激子自旋统计 反系间窜越 杂化局域-电荷转移态 激子理论
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基于高激子利用率的第三代有机电致发光材料的研究进展 被引量:1
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作者 高桂才 任铁钢 《化学研究》 CAS 2017年第2期150-156,共7页
荧光OLED材料由于受到激子统计规律的限制,其能量利用效率小于25%.为了开发高效而价廉的OLED材料,突破激子统计规律的研究受到了广泛关注,目前的研究主要集中在三个方向:突破激子统计限制的共轭聚合物材料、三线态反系间窜越(RISC)的延... 荧光OLED材料由于受到激子统计规律的限制,其能量利用效率小于25%.为了开发高效而价廉的OLED材料,突破激子统计规律的研究受到了广泛关注,目前的研究主要集中在三个方向:突破激子统计限制的共轭聚合物材料、三线态反系间窜越(RISC)的延迟荧光材料以及"热激子"(hot exciton)与杂化局域-电荷转移(HLCT)激发态材料.对近年来在基于高激子利用率的第三代有机电致发光材料的研究方面的进展情况进行综述,同时对其未来的研究前景进行了展望. 展开更多
关键词 激子统计 延迟荧光 杂化局域-电荷转移 T-T态激子湮灭 激子
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Identification and Quantification of Non-Spherical Particles 被引量:1
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作者 曾周末 张宝明 杨庆 《Transactions of Tianjin University》 EI CAS 2002年第2期75-78,共4页
In commercial applications of phase Doppler anemometry (PDA), the effectiveness of non sphericity of particles is present and the response of PDA system deviates from the theoretical prediction. In this paper, the st... In commercial applications of phase Doppler anemometry (PDA), the effectiveness of non sphericity of particles is present and the response of PDA system deviates from the theoretical prediction. In this paper, the statistic characteristics of PDA signal related to irregular particles is analyzed and a method of statistic classification of irregular particles is proposed.It proves that the parameter of PDA signal for irregular particles is an unbiased estimation for spherical ones, the mean of the phase difference is in direct proportion to the mean diameter of particles and the standard deviation of the phase difference increases linearly with the standard deviation of irregular particles. As an application of the identification of irregular objects, fuzzy patterns and similarities of haemocytes are used to recognize and quantify cell samples.The statistic classification of particles is more significant in practice. 展开更多
关键词 particle measurement phase Doppler anemometry statistic classification pattern recognition
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中子入射砷核同位素反应全套微观数据的计算与分析 被引量:1
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作者 魏波 张正军 +2 位作者 童楚楚 陈金根 胡继峰 《核技术》 CAS CSCD 北大核心 2018年第7期53-60,共8页
基于光学模型假设和中子与天然砷反应的总截面、去弹截面以及弹性散射角分布的实验数据,获得了一组0.1~20 MeV能量区域内普适于中子与砷核同位素反应的光学势参数。并以该组光学模型参数为前提,利用以光学模型、扭曲波Born近似理论、统... 基于光学模型假设和中子与天然砷反应的总截面、去弹截面以及弹性散射角分布的实验数据,获得了一组0.1~20 MeV能量区域内普适于中子与砷核同位素反应的光学势参数。并以该组光学模型参数为前提,利用以光学模型、扭曲波Born近似理论、统一的Hauser-Feshbach统计理论和激子模型等理论为核心的UNF程序,计算了中子与As及其同位素的反应截面、能谱和双微分截面值,并对理论计算值和实验数据进行了比较和分析,理论计算结果与实验数据符合较好,同时给出了无实验数据的区域的理论结果。 展开更多
关键词 全套中子微观核数据 光学模型 反应截面 Hauser-Feshbach统计理论与激子模型
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Bunching and Antibunching in Cavity QED
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作者 H.Jabri H.Eleuch 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第7期134-138,共5页
We study the statistics of the emitted filed from Rydberg atom confined inside a microcavity and interacting with a pump laser in the strong coupling regime. We explore the manifestation of the antibunching in connect... We study the statistics of the emitted filed from Rydberg atom confined inside a microcavity and interacting with a pump laser in the strong coupling regime. We explore the manifestation of the antibunching in connection with the internal system parameters. 展开更多
关键词 quantum fluctuations quantum noise photon statistics cavity quantum electrodynamics
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An Anyon Model in a Toric Honeycomb Lattice
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作者 梁龙 虞跃 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第1期80-84,共5页
We study an anyon model in a toric honeycomb lattice. The ground states and the low-lying excitations coincide with those of Kitaev toric code model and then the excitations obey mutual semionic statistics. This model... We study an anyon model in a toric honeycomb lattice. The ground states and the low-lying excitations coincide with those of Kitaev toric code model and then the excitations obey mutual semionic statistics. This model is helpful to understand the toric code of anyons in a more symmetric way. On the other hand, there is a direct relation between this toric honeycomb model and a boundary coupled Ising chain array in a square lattice via Jordan-Wigner transformation. We discuss the equivalence between these two models in the low-lying sector and realize these anyon excitations in a conventional fermion system. The analysis for the ground state degeneracy in the last section can also be thought of as a complementarity of our previous work [Phys. A: Math. Theor. 43 (2010) 105306]. 展开更多
关键词 ANYON toric code
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Progress in next-generation organic electroluminescent materials:material design beyond exciton statistics 被引量:11
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作者 YAO Liang YANG Bing MA YuGuang 《Science China Chemistry》 SCIE EI CAS 2014年第3期335-345,共11页
Exciton(or spin)statistics is a physical principle based on the statistics of spin multiplicity.In electroluminescence,injected electrons and holes have randomized spin states,and usually form singlet or triplet excit... Exciton(or spin)statistics is a physical principle based on the statistics of spin multiplicity.In electroluminescence,injected electrons and holes have randomized spin states,and usually form singlet or triplet excitons in the ratio of 1:3.Exciton statistics determines that the upper limit of internal quantum efficiency is 25%in fluorescent devices,since only singlet exciton can decay radiatively.However,both experimental and theoretical evidence indicate that the actual efficiency can exceed the exciton statistics limit of 25%by utilizing materials with special electronic structure and optimized device structures.These results bring light to break through the exciton statistics limit and develop new-generation fluorescent materials with low cost and high efficiency.Recently,the exciton statistics,which has attracted great attention in the past decade,is being rejuvenated due to the discovery of some fluorescent materials with abnormally high efficiencies.In view of their significance in theoretical research of organic semiconductors and developing new-generation OLED materials,such materials are widely investigated in both academic institutions and industry.Several key issues still require further clarification for this kind of materials,such as the molecular design concepts.Herein,we review the progress of the materials with efficiency exceeding the exciton statistics limit,and the routes to improve exciton utilization efficiency.In the end,we present an innovative pathway to fully harvest the excitons in fluorescent devices,namely,"hot exciton"model and relevant fluorescence material with hybridized local and charge-transfer(HLCT)excited state. 展开更多
关键词 organic light-emitting device(OLED) exciton statistics reverse intersystem crossing(RISC) hybridized local and charge-transfer(HLCT) hot exciton
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From electronic excited state theory to the property predictions of organic optoelectronic materials 被引量:4
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作者 SHUAI ZhiGang XU Wei +1 位作者 PENG Qian GENG Hua 《Science China Chemistry》 SCIE EI CAS 2013年第9期1277-1284,共8页
We introduce here a work package for a National Natural Science Foundation of China Major Project. We propose to develop computational methodology starting from the theory of electronic excitation processes to predict... We introduce here a work package for a National Natural Science Foundation of China Major Project. We propose to develop computational methodology starting from the theory of electronic excitation processes to predicting the opto-electronic property for organic materials, in close collaborations with experiments. Through developing methods for the electron dynamics, considering superexchange electronic couplings, spin-orbit coupling elements between excited states, electron-phonon relaxation, intermolecular Coulomb and exchange terms we combine the statistical physics approaches including dynamic Monte Carlo, Boltzmann transport equation and Boltzmann statistics to predict the macroscopic properties of opto-electronic materials such as light-emitting efficiency, charge mobility, and exciton diffusion length. Experimental synthesis and characterization of D-A type ambipolar transport material as well as novel carbon based material will provide a test ground for the verification of theory. 展开更多
关键词 electron dynamics methods statistical physics approaches light-emitting efficiency charge mobility exciton diffusion
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