准一维有机半导体中元激发碰撞动力学
摘要
近年来,随着理论研究方法的不断改进和实验手段的不断提高,对有机半导体材料的研究,已经发展成为系统的多学科交叉的充满活力的领域。有机半导体材料通常可以分为两类:有机小分子(或低聚物)和有机聚合物。人们对有机聚合物的研究最为广泛和深入。作为一种新型的功能材料,有机聚合物既具有金属和半导体的电子特性,又具有聚合物的易加工、柔韧性、价格低廉等优点,成为近年来的研究热点。目前,人们已经研制出各种各样的有机光电子器件,如有机发光二极管、场效应管、光伏电池等。这些器件的工作原理一般都是基于电荷注入、电荷传输以及电子—空穴复合这些物理过程。
有机聚合物具有不同于传统半导体的特性,如有机材料中存在很强的电子—声子相互作用,电子态和晶格态两者相互影响,因此,聚合物中的载流子不再是传统的电子或空穴,而是电荷的自陷元激发,如孤子、极化子、双极化子等准粒子。通过光激发或正、负极化子的复合,聚合物中还会形成激子,激子则通过辐射或非辐射跃迁回到基态。激子与聚合物的发光现象有着紧密的联系。因此,研究聚合物中载流子和激子之间的相互作用对我们理解聚合物的发光以及输运性质有着重要意义。
本文采用一维紧束缚近似的SSH模型,利用非绝热动力学的方法,主要研究了有机共轭聚合物中极化子与激子,双极化子与激子在外电场作用下的碰撞过程。本论文的具体研究内容和主要计算结果如下:
1.极化子与激子的碰撞过程分析
碰撞过程使得极化子和激子的晶格位形及电子态都发生了较大变化:在小电场下,极化子和激子相遇后会复合到一起形成荷电激子态。继续增加电场,极化子和激子相遇后彼此穿过对方。碰撞过程引起了较剧烈的幅模振荡,能隙中出现振荡的局域能级,表明有新的局域电子态产生。在强电场下,极化子和激子碰撞后极化子会被解体,激子的位形基本保持不变。极化子与三重态激子主要存在三个反应通道:(1) P_↓+T→P_↑+S,(2) P+T→G+P~*,(3)P+T→T+e。其中,P代表极化子,箭头表示极化子的自旋方向,T代表三重态激子,S代表单重态激子,G是基态,P~*代表极化子激发态,e代表自由电荷。各反应通道的几率与电场强度有一定的依赖关系。由于单重态激子和激发态极化子都可以通过辐射跃迁回到基态,显然,极化子和三重态激子的碰撞将有助于聚合物的发光。
2.双极化子与激子的碰撞过程研究
双极化子遇到激子时,把它携带的一部分电荷转移到激子上,从而形成两个新的准粒子,分别是极化子和激发态的极化子。其中激发态的极化子可以通过辐射跃迁回到基态,这个过程中释放一个光子。所以,双极化子和三重态激子的碰撞将有助于提高聚合物的发光效率。
In recent years, with improvement of experimental instruments and the development of theoretical methods, the research on organic semiconductors has been developed into a systematic and multidisciplinary field. Organic semiconductors can be broadly classified into two categories: small molecules or oligomers and polymers, in which polymers attract much attention and research. As a new kind of functional material, polymers have been the focus of the research work both because of the processing and performance advantages for low-cost and large-area application. In the past twenty years, many photoelectric devices based on conjugated polymers have offered promise for use in applications from experiment, such as light-emitting diodes (LEDs), field effect transistors photovoltaic cells, etc.. The work principle of these devices is mainly based on the physical processes involving charge injection, charge transport and electron-hole recombination.
Contrast to the traditional semiconductor, organic semiconductor has its unique properties. First, most of polymers have qusi-one-dimensional structure due to the weak interaction force between the organic molecules. Second, owning to its soft properties, there are strong electron-phonon couplings in organic systems. It is generally believed that these excitations, such as solitons, polarons and bipolarons, are related to charge carriers in conjugated polymers. By photoexcitation or electron-hole combination, excitons can be formed in conjugated polymers. These elementary excitations are of fundamental importance for charge transport and photoluminescence of conjugated polymers. Studies on the dynamical and collision processes of these excitations are elements to understand the optoelectronics for the organic materials.
In the paper, based on the one-dimensional tight-binding Su-Schrieffer-Heeger(SSH) model, by using a nonadiamatic molecular dynamic method, we simulate collision between polaron (bipolaron) and triplet exciton in conjugated polymers. The main results for our investigation in this paper are in the following:
1. Investigation for collision between polaron and triplet exciton
The results of our simulations show that the lattice structure and the electronic state of the polaron and the exciton are changed very much in the collision process. Firstly, at lower electric field , the polaron will combine with the exciton and formed a charged exciton. Secondly, at mediate field strength, the polaron and the exciton will pass through each other. In the process of the collision, the lattice oscillated by large amplitude and at the same time an energy level appeared in energy gap. This means that there are new localized states are excited due to the collision. Thirdly, In stronger field strength, the polaron will be dissociated after the collision with the exciton. Thereare three channels for the polaron-triplet reaction: (1) P_↓+T→P_↑+S , (2)P + T→G + P~*, (3) P + T→T + e, where P denote a polaron and the arrowdenote the spin state of the polaron, T a triplet exciton, S a singlet exciton, G theground state and e a free charge. The probability of each channel depends on theexternal electric fields. Due to the radiatively decay of the singlet exciton and theexcited polaron, the polaron-triplet collision will contribute to the efficiency ofelectroluminescence.
2. Investigation for collision between bipolaron and exciton
It is found that when a bipolaron collides with an exciton, the bipolaron transfers some charges to the exciton. By this way, two new qusi-excitations are formed: one is polaron and the other is excited polaron. The excited polaron can decay to the ground state through emitting a photon. Therefore, the collision between bipolarons and triplet excitons can enhance the efficiency of electroluminescence.
有机聚合物具有不同于传统半导体的特性,如有机材料中存在很强的电子—声子相互作用,电子态和晶格态两者相互影响,因此,聚合物中的载流子不再是传统的电子或空穴,而是电荷的自陷元激发,如孤子、极化子、双极化子等准粒子。通过光激发或正、负极化子的复合,聚合物中还会形成激子,激子则通过辐射或非辐射跃迁回到基态。激子与聚合物的发光现象有着紧密的联系。因此,研究聚合物中载流子和激子之间的相互作用对我们理解聚合物的发光以及输运性质有着重要意义。
本文采用一维紧束缚近似的SSH模型,利用非绝热动力学的方法,主要研究了有机共轭聚合物中极化子与激子,双极化子与激子在外电场作用下的碰撞过程。本论文的具体研究内容和主要计算结果如下:
1.极化子与激子的碰撞过程分析
碰撞过程使得极化子和激子的晶格位形及电子态都发生了较大变化:在小电场下,极化子和激子相遇后会复合到一起形成荷电激子态。继续增加电场,极化子和激子相遇后彼此穿过对方。碰撞过程引起了较剧烈的幅模振荡,能隙中出现振荡的局域能级,表明有新的局域电子态产生。在强电场下,极化子和激子碰撞后极化子会被解体,激子的位形基本保持不变。极化子与三重态激子主要存在三个反应通道:(1) P_↓+T→P_↑+S,(2) P+T→G+P~*,(3)P+T→T+e。其中,P代表极化子,箭头表示极化子的自旋方向,T代表三重态激子,S代表单重态激子,G是基态,P~*代表极化子激发态,e代表自由电荷。各反应通道的几率与电场强度有一定的依赖关系。由于单重态激子和激发态极化子都可以通过辐射跃迁回到基态,显然,极化子和三重态激子的碰撞将有助于聚合物的发光。
2.双极化子与激子的碰撞过程研究
双极化子遇到激子时,把它携带的一部分电荷转移到激子上,从而形成两个新的准粒子,分别是极化子和激发态的极化子。其中激发态的极化子可以通过辐射跃迁回到基态,这个过程中释放一个光子。所以,双极化子和三重态激子的碰撞将有助于提高聚合物的发光效率。
In recent years, with improvement of experimental instruments and the development of theoretical methods, the research on organic semiconductors has been developed into a systematic and multidisciplinary field. Organic semiconductors can be broadly classified into two categories: small molecules or oligomers and polymers, in which polymers attract much attention and research. As a new kind of functional material, polymers have been the focus of the research work both because of the processing and performance advantages for low-cost and large-area application. In the past twenty years, many photoelectric devices based on conjugated polymers have offered promise for use in applications from experiment, such as light-emitting diodes (LEDs), field effect transistors photovoltaic cells, etc.. The work principle of these devices is mainly based on the physical processes involving charge injection, charge transport and electron-hole recombination.
Contrast to the traditional semiconductor, organic semiconductor has its unique properties. First, most of polymers have qusi-one-dimensional structure due to the weak interaction force between the organic molecules. Second, owning to its soft properties, there are strong electron-phonon couplings in organic systems. It is generally believed that these excitations, such as solitons, polarons and bipolarons, are related to charge carriers in conjugated polymers. By photoexcitation or electron-hole combination, excitons can be formed in conjugated polymers. These elementary excitations are of fundamental importance for charge transport and photoluminescence of conjugated polymers. Studies on the dynamical and collision processes of these excitations are elements to understand the optoelectronics for the organic materials.
In the paper, based on the one-dimensional tight-binding Su-Schrieffer-Heeger(SSH) model, by using a nonadiamatic molecular dynamic method, we simulate collision between polaron (bipolaron) and triplet exciton in conjugated polymers. The main results for our investigation in this paper are in the following:
1. Investigation for collision between polaron and triplet exciton
The results of our simulations show that the lattice structure and the electronic state of the polaron and the exciton are changed very much in the collision process. Firstly, at lower electric field , the polaron will combine with the exciton and formed a charged exciton. Secondly, at mediate field strength, the polaron and the exciton will pass through each other. In the process of the collision, the lattice oscillated by large amplitude and at the same time an energy level appeared in energy gap. This means that there are new localized states are excited due to the collision. Thirdly, In stronger field strength, the polaron will be dissociated after the collision with the exciton. Thereare three channels for the polaron-triplet reaction: (1) P_↓+T→P_↑+S , (2)P + T→G + P~*, (3) P + T→T + e, where P denote a polaron and the arrowdenote the spin state of the polaron, T a triplet exciton, S a singlet exciton, G theground state and e a free charge. The probability of each channel depends on theexternal electric fields. Due to the radiatively decay of the singlet exciton and theexcited polaron, the polaron-triplet collision will contribute to the efficiency ofelectroluminescence.
2. Investigation for collision between bipolaron and exciton
It is found that when a bipolaron collides with an exciton, the bipolaron transfers some charges to the exciton. By this way, two new qusi-excitations are formed: one is polaron and the other is excited polaron. The excited polaron can decay to the ground state through emitting a photon. Therefore, the collision between bipolarons and triplet excitons can enhance the efficiency of electroluminescence.
引文
[1]C. K. Chang, C. R. Fincher, Y. W. Park, A. J. Heeger, H. Shirakawa, E. J. Louis, S. C. Gau, and A. G. MacDiarmid, Phys. Rev. Lett. 39,1098-1101 (1977)
[2]H. Shirakawa, E. J. Louis, A. G. MacDiarmid et al, J. Chem. Soc. Chem. Commun.578 (1977)
[3]C. K. Chang, E. J. Louis, M. A. Druy et al., J. Am. Chem. Soc. 100,1013 (1978)
[4]Y.-W. Park, A. J. Heeger, M. A. Druy, and A. G. MacDiarmid, J. Chem. Phys.73,946-957(1980)
[5]H. Naarmann, and N. Theophilou, Synth Met. 22,1 (1987)
[6]W. J. Feast, J. Tsibouklis, K. L. Pouwer, L. Gronendaal, and E. W. Meijer, polymer 37,5017(1996)
[7]L. Pavesi, and M. Guzzi, J. Appl. Phys. 75,4779 (1994)
[8]H. J. Ko, Y. F. Chen, Z. Zhu, and T. Yao, Appl. Phys. Lett. 76, 1905 (2000)
[9]W. S. Shen, S. C. Shen, Y. Chang, et al. Infrared Phys. Technol. 37, 509 (1996)
[10] A. M. Stoneham, M. M. D. Ramos, A. M. Almeida, H. M. G. Correia, R. M.Ribeiro, H. Ness, and A. J. Fisher, J. Phys.: Condens. Matter. 14, 9877 (2002)
[11] M. Pope, H. P. Kallmann, and P. Magnante, J. Chem. Phys. 38, 2042 (1963)
[12]W. Helfrich, and W. G. Schneider, Phys. Rev. Lett. 14, 229 (1965)
[13]D. F. Williams, and M.Schadt, Proc. IEEE. 58,476 (1970)
[14]P. S. Vincett, W. A. Barlow, R. A. Hann, and G. G. Roberts, Thin Solid Films, 94,171 (1982)
[15]R. H. Partridge, Polymer, 24, 755 (1983)
[16]J. C. Carter, I. Grizzi, S. K. Heeks, D. J. Lacey, and S. G. Latham, et al, Appl.Phys. Lett, 71,34 (1997)
[17]G. Sakamoto, C. Adachi, T. Koyama, and Y. Taniguchi, Appl. Phys. Lett, 75, 766(1999)
[18]A. J. Heeger, S. Kivelson, J. R. Schrieffer, and W. P. Su, Rev. Mod. Phys. 60, 781(1988)
[19] 孙鑫 物理学进展 61 (1986)
[20] S. A. Brazovskii and N. N. Kirova, Pis'ma Zh. Eksp. Teor. Fiz 33, 6 (1981) [JETP Lett.33,4(1981)
[21]G. M. e Silva, Phys. Rev. B 61, 10777 (2000)
[22] Y. Qiu, Z. An, and C. Q. Wu, Synth Met. 135, 503 (2003)
[23] C. Q. Wu, Y. Qiu, Z. An, and K. Nasu, Phys. Rev. B 68, 125416 (2003)
[24]Fesser K 1989 Phys. Rev. B40 1962
[25] P. S. Davids, A. Saxena, and D. L. Smith, Phys. Rev. B 53,4823 (1996)
[26]Xie Shi-Jie, Wei Jian-Hua, Liu De-Sheng et al 1997 Phys. Rev. B56 13162
[27]Li Z J., Lin H Q, Yao K L 1997 Z. Phys. B104 77
[28]An Z, Li Z J, Liu Z L, Yao K L 1994 Acta Phys.Sin.43 516
[29]S. Li, L. S. Chen, T. H. George, and X. Sun, Phys. Rev. B 70, 075201 (2004)
[30]Wang L X, Zhang D C, Liu D S, Han S H, Xie S J 2003 Acta Phys.Sin. 52 2547
[31] S. Li, L. S. Chen, T. H. George, and X. Sun, Phys. Rev. B 70, 075201 (2004)
[32]M. D. McGehee and A. J. Heeger, Adv. Mat. 12, 828 (2000)
[33]D. Mose, A. Dogariu, A.J. Heeger, Phys. Rev. B 61, 9373 (2000)
[34] N. C. Granstrom, K. Petritsch, A. C. Arias, A. Lux, M. R. Andersson, and R. H.Friend, Nature 395, 257 (1998)
[35] J. Szmytkowski, W. Stampor, and J. Kalinowski, and Z. H. Kafafi, Appl. Phys.Lett. 80,1465 (2002)
[36] Z.Shuai, D.Bljonne and R.J.Silbey, Singlet and triplet exciton formation rates in conjugated polymer light-emitting diodes, Phys.Rev.Lett.84,131(2000)
[37] R. H. Friend et al., Nature 397, 121 (1999); N. K. Mark and R. B. Eric, Phys. Rev.B 62,11473(2000)
[38] A. S. Dhoot, D.S. Ginger, D. Beljonne, Z. Shuai, and N. C. Greenham, Chem.Phys. Lett. 88,197401 (2002)
[39] J. S. Wilson, A. S. Dhoot, A. J. A. B. Seeley, M. S. Khan, A. Kohler, and R. H.Frend, Nature 413,828 (2001),
[40] P. K. H. Ho, J. Kim, J. H. Burroughes, H. Becker, S. F. Y. Li, T. M. Brown, F.Caeialli, and R. H. Friend, Nature 404,481 (2000)
[41]A.B.Walker,A.Kamnili,and S.J.Martin,J.Phys:Condens.Matter 14,9825(2002)
[42]C.W.Tang and S.A.Vanslyke,Appl.Phys.Lett.51,913(1987)
[43]B.H.Cumpston and K.F.Jensen,Synth Met.73,195(1995)
[44]Y.Yang and A.J.Heeger,Appl Phys Lett.64,1245(1994)
[45]Y.Yang,E.Westerweele,C.Zhang,P.Smith,and A.J.Heeger,J Appl.Phys.77,694(1995)
[46]Y.E.Kim,H.Park and J.J.Kim,Appl.Phys.Lett.69,599(1996)
[47]K.H.Ho.Peter et al.,Adv.Mater.10,769(1998)
[48]S.J.Chung et al.,Adv.Mater.10,1112(1998)
[49]P.W.M.Blom,M.J.M.De Jong and J.J.M.Vleggaar,Appl.Phys.Lett.68,3308(1996)
[50]I.H.Campbell et al.,Appl.Phys.Lett.71,3528(1997)
[51]M.St(o|¨)Bel et al.,Phys.Chem.Chem.Phys.1,1791(1999)
[52]Z.Shuai,D.Bljonne and R.J.Silbey,Singlet and triplet exciton formation rates in conjugated polymer light-emitting diodes,Phys.Rev.Lett.84,131(2000)
[53]M.Wohlgenannt,Kunj Tandon and S.Mazumdar,Formation cross-sections of singlet and triplet excitons in π -conjugated polymers,Nature 409,494(2001)
[54]Tzay-Ming Hong,Hsin-Fei Meng,Spin-dependent recombination and electroluminescence quantum yield in conjugated polymers,Phys.Rev.B 63,075206(2001)
[55]孙震,安忠,李元,刘文,刘德胜,解士杰,物理学报58(2009)高聚物中极化子和三重态激子的碰撞过程研究
[56]M.Segal,M.K.Lee and Z.G.Zoos,Frequency response and origin of the spin-1/2photoluminescence-detected magnetic resonance in a π-conjugated polymer,Phys.Rev.B 71,245201(2005)
[57]M.K.Lee,M.Segal and Z.G.Soo,Yield of Singlet Excitons in Organic Light-Emitting Devices:A Double Modulation Photoluminescence-Detected Magnetic Study,Phys.Rev.Lett.94,137403(2005)
[1]Sirringhaus H.,Tessler N.& Friend R.H.1998 Science 280,1741
[2]M.Granstrom,K.Petritsch,A.C.Arias,A.Lux,M.R.Anderson and R.H.Friend 1998 Nature 395,257
[3]Braun D.& Heeger A.J.1991 Appl.Phys.Lett.58,1982
[4]C.Q.Wu,Y.Qiu,Z.An & K.Nasu 2003 Phys.Rev.B 68,125416
[5]Z.An,C.Q.Wu 2003 Synthetic Metals 137,1151
[6]Yukihiro Shimoi,Shuji Abe 1994 Phys.Rev.B 49,14113
[7]M.Segal,M.A.Baldo,R.J.Holmes,S.R.Forrest and Z.G.Soos 2003 Phys.Rev.B 68,075211
[8]M.Segal,M.A.Baldo,M.K.Lee,J.Shinar and Z.G.Soos 2005 Phys.Rev.B 71,245201
[9]Han-Yong Choi,Michael J.Rice 1991 Phys.Rev.B 44,10521
[10]S.A.Brazovskii and N.N.Kirova,1981 JETP Lett.33,4.
[11]W.P.Su,J.R.Schrieffer and A.J.Heeger,1980 Phys.Rev.B 22,2099
[12]Wu C Q,Qiu Y,An Z,and Nasu K.Dynamical study on polaron formation in a metal/polymer/metal structure[J].Phys Rev B,2003,68:125416.
[13]Fu J Y,Ren J F,Liu X J,Liu D S,and Xie S J.Dynamics of charge injection into an open conjugated polymer:A nonadiabatic approach[J].Phys Rev B,2006,73:195401.
[14]王鹿霞、张大成、刘德胜、韩圣浩、解士杰.基态非简并聚合物中的极化子和双极化子动力学[J].物理学报,2003,52:2547-2552.
[15]Johansson A and Stafstr(o|¨)m S.Polaron Dynamics in a System of Coupled Conjugated Polymer Chains[J].Phys Rev Lett,2001,86:3602-3605.
[16]Rakhrnanova S V and Conwell E M.Polaron dissociation in conducting polymers by high electric fields[J].Appl Phys Lett,1999,75:1518-1520.
[17]孙震,安忠,李元,刘文,刘德胜,解士杰,物理学报58(2009)高聚物中极化子和三重态激子的碰撞过程研究
[18]Makoto Kuwabara,Yoshiyuki Ono and Akira Terai,Motion of charged soliton in polyacetylene due to electric field.Ⅱ.Behavior of width,Journal of The Physical Society of Japan 60,1286-1993(1991)
[1]A. J. Heeger, S. Kivelson, J. R. SchriefFer and W.P. Su, Rev. Mod. Phys. 60, 781(1988)
[2]S.Brazovskii and N.Kirova, Sov. Phys. JETP Lett. 33, 4 (1981);D. K. Campbell, A.R. Bishop, and K. Fesser, Phys. Rev. B 26,6862 (1982)
[3]Primary Photoexcitation in Conjugated Polymers: Molecular Exciton versus Semiconductor Band Model, edited by N. S.Sariciftci (World Scientific, Singapore,1997)
[4]F. Genoud, M. Guglielmi, M. Nechtschein, E. Genies and M. Salmon,Phys. Rev.Lett. 55,118(1984)
[5]P. A. Lane, X. Wei and Z. V. Vardeny, Phys. Rev. Lett. 77, 1544 (1996)
[6] Yukihiro Shimoi and Shuji Abe, Phys. Rev. B 50,14781 (1994)
[7]Z. Xie, Y. M. Kang, Z. An, Y. C. Li, Phys. Rev. B 61, 1096 (2000)
[8]Han-Yong Choi and Michael J. Rice, Phys. Rev. B 44,10521 (1991)
[9]L. S. Swanson, J. Shinar, A. R. Brown, D. D. C. Bradley, R. H. Friend, P. L. Burn, A.Kraft and A. B. Holmes, Phys. Rev. B46,15072 (1992)
[10]Kun Gao, Xiaojing Liu, Desheng Liu and Shijie Xie, Phys. Rev. B75, 205412(2007)
[11]Wu C Q, Qiu Y, An Z, and Nasu K. Dynamical study on polaron formation in a metal/polymer/metal structure [J]. Phys Rev B, 2003,68: 125416.
[2]H. Shirakawa, E. J. Louis, A. G. MacDiarmid et al, J. Chem. Soc. Chem. Commun.578 (1977)
[3]C. K. Chang, E. J. Louis, M. A. Druy et al., J. Am. Chem. Soc. 100,1013 (1978)
[4]Y.-W. Park, A. J. Heeger, M. A. Druy, and A. G. MacDiarmid, J. Chem. Phys.73,946-957(1980)
[5]H. Naarmann, and N. Theophilou, Synth Met. 22,1 (1987)
[6]W. J. Feast, J. Tsibouklis, K. L. Pouwer, L. Gronendaal, and E. W. Meijer, polymer 37,5017(1996)
[7]L. Pavesi, and M. Guzzi, J. Appl. Phys. 75,4779 (1994)
[8]H. J. Ko, Y. F. Chen, Z. Zhu, and T. Yao, Appl. Phys. Lett. 76, 1905 (2000)
[9]W. S. Shen, S. C. Shen, Y. Chang, et al. Infrared Phys. Technol. 37, 509 (1996)
[10] A. M. Stoneham, M. M. D. Ramos, A. M. Almeida, H. M. G. Correia, R. M.Ribeiro, H. Ness, and A. J. Fisher, J. Phys.: Condens. Matter. 14, 9877 (2002)
[11] M. Pope, H. P. Kallmann, and P. Magnante, J. Chem. Phys. 38, 2042 (1963)
[12]W. Helfrich, and W. G. Schneider, Phys. Rev. Lett. 14, 229 (1965)
[13]D. F. Williams, and M.Schadt, Proc. IEEE. 58,476 (1970)
[14]P. S. Vincett, W. A. Barlow, R. A. Hann, and G. G. Roberts, Thin Solid Films, 94,171 (1982)
[15]R. H. Partridge, Polymer, 24, 755 (1983)
[16]J. C. Carter, I. Grizzi, S. K. Heeks, D. J. Lacey, and S. G. Latham, et al, Appl.Phys. Lett, 71,34 (1997)
[17]G. Sakamoto, C. Adachi, T. Koyama, and Y. Taniguchi, Appl. Phys. Lett, 75, 766(1999)
[18]A. J. Heeger, S. Kivelson, J. R. Schrieffer, and W. P. Su, Rev. Mod. Phys. 60, 781(1988)
[19] 孙鑫 物理学进展 61 (1986)
[20] S. A. Brazovskii and N. N. Kirova, Pis'ma Zh. Eksp. Teor. Fiz 33, 6 (1981) [JETP Lett.33,4(1981)
[21]G. M. e Silva, Phys. Rev. B 61, 10777 (2000)
[22] Y. Qiu, Z. An, and C. Q. Wu, Synth Met. 135, 503 (2003)
[23] C. Q. Wu, Y. Qiu, Z. An, and K. Nasu, Phys. Rev. B 68, 125416 (2003)
[24]Fesser K 1989 Phys. Rev. B40 1962
[25] P. S. Davids, A. Saxena, and D. L. Smith, Phys. Rev. B 53,4823 (1996)
[26]Xie Shi-Jie, Wei Jian-Hua, Liu De-Sheng et al 1997 Phys. Rev. B56 13162
[27]Li Z J., Lin H Q, Yao K L 1997 Z. Phys. B104 77
[28]An Z, Li Z J, Liu Z L, Yao K L 1994 Acta Phys.Sin.43 516
[29]S. Li, L. S. Chen, T. H. George, and X. Sun, Phys. Rev. B 70, 075201 (2004)
[30]Wang L X, Zhang D C, Liu D S, Han S H, Xie S J 2003 Acta Phys.Sin. 52 2547
[31] S. Li, L. S. Chen, T. H. George, and X. Sun, Phys. Rev. B 70, 075201 (2004)
[32]M. D. McGehee and A. J. Heeger, Adv. Mat. 12, 828 (2000)
[33]D. Mose, A. Dogariu, A.J. Heeger, Phys. Rev. B 61, 9373 (2000)
[34] N. C. Granstrom, K. Petritsch, A. C. Arias, A. Lux, M. R. Andersson, and R. H.Friend, Nature 395, 257 (1998)
[35] J. Szmytkowski, W. Stampor, and J. Kalinowski, and Z. H. Kafafi, Appl. Phys.Lett. 80,1465 (2002)
[36] Z.Shuai, D.Bljonne and R.J.Silbey, Singlet and triplet exciton formation rates in conjugated polymer light-emitting diodes, Phys.Rev.Lett.84,131(2000)
[37] R. H. Friend et al., Nature 397, 121 (1999); N. K. Mark and R. B. Eric, Phys. Rev.B 62,11473(2000)
[38] A. S. Dhoot, D.S. Ginger, D. Beljonne, Z. Shuai, and N. C. Greenham, Chem.Phys. Lett. 88,197401 (2002)
[39] J. S. Wilson, A. S. Dhoot, A. J. A. B. Seeley, M. S. Khan, A. Kohler, and R. H.Frend, Nature 413,828 (2001),
[40] P. K. H. Ho, J. Kim, J. H. Burroughes, H. Becker, S. F. Y. Li, T. M. Brown, F.Caeialli, and R. H. Friend, Nature 404,481 (2000)
[41]A.B.Walker,A.Kamnili,and S.J.Martin,J.Phys:Condens.Matter 14,9825(2002)
[42]C.W.Tang and S.A.Vanslyke,Appl.Phys.Lett.51,913(1987)
[43]B.H.Cumpston and K.F.Jensen,Synth Met.73,195(1995)
[44]Y.Yang and A.J.Heeger,Appl Phys Lett.64,1245(1994)
[45]Y.Yang,E.Westerweele,C.Zhang,P.Smith,and A.J.Heeger,J Appl.Phys.77,694(1995)
[46]Y.E.Kim,H.Park and J.J.Kim,Appl.Phys.Lett.69,599(1996)
[47]K.H.Ho.Peter et al.,Adv.Mater.10,769(1998)
[48]S.J.Chung et al.,Adv.Mater.10,1112(1998)
[49]P.W.M.Blom,M.J.M.De Jong and J.J.M.Vleggaar,Appl.Phys.Lett.68,3308(1996)
[50]I.H.Campbell et al.,Appl.Phys.Lett.71,3528(1997)
[51]M.St(o|¨)Bel et al.,Phys.Chem.Chem.Phys.1,1791(1999)
[52]Z.Shuai,D.Bljonne and R.J.Silbey,Singlet and triplet exciton formation rates in conjugated polymer light-emitting diodes,Phys.Rev.Lett.84,131(2000)
[53]M.Wohlgenannt,Kunj Tandon and S.Mazumdar,Formation cross-sections of singlet and triplet excitons in π -conjugated polymers,Nature 409,494(2001)
[54]Tzay-Ming Hong,Hsin-Fei Meng,Spin-dependent recombination and electroluminescence quantum yield in conjugated polymers,Phys.Rev.B 63,075206(2001)
[55]孙震,安忠,李元,刘文,刘德胜,解士杰,物理学报58(2009)高聚物中极化子和三重态激子的碰撞过程研究
[56]M.Segal,M.K.Lee and Z.G.Zoos,Frequency response and origin of the spin-1/2photoluminescence-detected magnetic resonance in a π-conjugated polymer,Phys.Rev.B 71,245201(2005)
[57]M.K.Lee,M.Segal and Z.G.Soo,Yield of Singlet Excitons in Organic Light-Emitting Devices:A Double Modulation Photoluminescence-Detected Magnetic Study,Phys.Rev.Lett.94,137403(2005)
[1]Sirringhaus H.,Tessler N.& Friend R.H.1998 Science 280,1741
[2]M.Granstrom,K.Petritsch,A.C.Arias,A.Lux,M.R.Anderson and R.H.Friend 1998 Nature 395,257
[3]Braun D.& Heeger A.J.1991 Appl.Phys.Lett.58,1982
[4]C.Q.Wu,Y.Qiu,Z.An & K.Nasu 2003 Phys.Rev.B 68,125416
[5]Z.An,C.Q.Wu 2003 Synthetic Metals 137,1151
[6]Yukihiro Shimoi,Shuji Abe 1994 Phys.Rev.B 49,14113
[7]M.Segal,M.A.Baldo,R.J.Holmes,S.R.Forrest and Z.G.Soos 2003 Phys.Rev.B 68,075211
[8]M.Segal,M.A.Baldo,M.K.Lee,J.Shinar and Z.G.Soos 2005 Phys.Rev.B 71,245201
[9]Han-Yong Choi,Michael J.Rice 1991 Phys.Rev.B 44,10521
[10]S.A.Brazovskii and N.N.Kirova,1981 JETP Lett.33,4.
[11]W.P.Su,J.R.Schrieffer and A.J.Heeger,1980 Phys.Rev.B 22,2099
[12]Wu C Q,Qiu Y,An Z,and Nasu K.Dynamical study on polaron formation in a metal/polymer/metal structure[J].Phys Rev B,2003,68:125416.
[13]Fu J Y,Ren J F,Liu X J,Liu D S,and Xie S J.Dynamics of charge injection into an open conjugated polymer:A nonadiabatic approach[J].Phys Rev B,2006,73:195401.
[14]王鹿霞、张大成、刘德胜、韩圣浩、解士杰.基态非简并聚合物中的极化子和双极化子动力学[J].物理学报,2003,52:2547-2552.
[15]Johansson A and Stafstr(o|¨)m S.Polaron Dynamics in a System of Coupled Conjugated Polymer Chains[J].Phys Rev Lett,2001,86:3602-3605.
[16]Rakhrnanova S V and Conwell E M.Polaron dissociation in conducting polymers by high electric fields[J].Appl Phys Lett,1999,75:1518-1520.
[17]孙震,安忠,李元,刘文,刘德胜,解士杰,物理学报58(2009)高聚物中极化子和三重态激子的碰撞过程研究
[18]Makoto Kuwabara,Yoshiyuki Ono and Akira Terai,Motion of charged soliton in polyacetylene due to electric field.Ⅱ.Behavior of width,Journal of The Physical Society of Japan 60,1286-1993(1991)
[1]A. J. Heeger, S. Kivelson, J. R. SchriefFer and W.P. Su, Rev. Mod. Phys. 60, 781(1988)
[2]S.Brazovskii and N.Kirova, Sov. Phys. JETP Lett. 33, 4 (1981);D. K. Campbell, A.R. Bishop, and K. Fesser, Phys. Rev. B 26,6862 (1982)
[3]Primary Photoexcitation in Conjugated Polymers: Molecular Exciton versus Semiconductor Band Model, edited by N. S.Sariciftci (World Scientific, Singapore,1997)
[4]F. Genoud, M. Guglielmi, M. Nechtschein, E. Genies and M. Salmon,Phys. Rev.Lett. 55,118(1984)
[5]P. A. Lane, X. Wei and Z. V. Vardeny, Phys. Rev. Lett. 77, 1544 (1996)
[6] Yukihiro Shimoi and Shuji Abe, Phys. Rev. B 50,14781 (1994)
[7]Z. Xie, Y. M. Kang, Z. An, Y. C. Li, Phys. Rev. B 61, 1096 (2000)
[8]Han-Yong Choi and Michael J. Rice, Phys. Rev. B 44,10521 (1991)
[9]L. S. Swanson, J. Shinar, A. R. Brown, D. D. C. Bradley, R. H. Friend, P. L. Burn, A.Kraft and A. B. Holmes, Phys. Rev. B46,15072 (1992)
[10]Kun Gao, Xiaojing Liu, Desheng Liu and Shijie Xie, Phys. Rev. B75, 205412(2007)
[11]Wu C Q, Qiu Y, An Z, and Nasu K. Dynamical study on polaron formation in a metal/polymer/metal structure [J]. Phys Rev B, 2003,68: 125416.