تاثیر افزایش تعداد مولکول ها در توان گرمای مولکول C20

نوع مقاله : مقاله پژوهشی کامل

نویسندگان

1 دانشگاه گیلان

2 آزمایشگاه نانوفیزیک محاسباتی، گروه فیزیک دانشکده علوم پایه، دانشگاه گیلان

چکیده

در این پژوهش، خواص توان گرمایی مولکول فولرن C20 و اثر افزایش تعداد مولکول با استفاده از نظریه تابعی چگالی و فرموﻝبندی تابع گرین در رژیم پاسخ خطی بررسی شده است. ما سه ارایش متفاوت: Au- C20 - Au, Au- (C20)2- Au وسرانجامAu- (C20)3 – Au را در نظر می گیریم. محاسبات نشان ﻣﻲدهد که با افزایش تعداد مولکول فولرن C20 توان گرمایی افزایش ﻣﻲیابد. بعلاوه، علامت ضریب سیبک به طول وابسته است و ﻣﻲتواند برای تعداد مختلفی از مولکوﻝهای فولرن C20، مثبت (نوع p) یا منفی (نوع n) باشد. توان گرمایی، عدد شایستگی را در سیستم افزایش ﻣﻲدهد و منجر به بازدهی بیشتر وسیله ترموالکتریک خواهد شد.

کلیدواژه‌ها


عنوان مقاله [English]

Impact of increasing the number of molecules in thermopower properties of C20 molecule

نویسنده [English]

  • Hita Khalatbari 2
1
2 Computational Nanophysics Laboratory (CNL), Department of Physics, University of Guilan, Rasht, Iran
چکیده [English]

In this research, thermopower properties of C20 fullerene molecule and the effect of increasing the number of molecule is investigated using density functional theory and Green’s function formalism in linear response regime. We consider three different configuration: Au- C20 - Au, Au- (C20)2- Au and finally Au- (C20)3 – Au. The calculation show that increasing the number of C20 fullerene molecules in the device increases the molecular thermopower. In addition, the signs of the seebeck coefficient are length dependent and can be positive (p type) or negative (n type) for different number of C20 fullerene molecules. Thermopower, increases the figure of merit in the system and will lead to more efficient thermoelectric Device.

کلیدواژه‌ها [English]

  • Thermopower
  • C20 fullerene
  • Density functional theory
  • Green’s function
[1] P. Reddy, S.Y. Jang, R.A. Segalman, A. Majumdar, Thermoelectricity in molecular junctions, Science 315 (2007) 1568-1571.          
 
[2] K. Baheti, J.A. Malen, P. Doak, P. Reddy, S.Y. Jang, T.D. Tilley, R.A. Segalman, Probing the chemistry of molecular heterojunctions using thermoelectricity, Nano letters 8 (2008) 715-719.
 
[3] J.R. Sootsman, D.Y. Chung, M.G. Kanatzidis, New and old concepts in thermoelectric materials, Angewandte Chemie International Edition 48 (2009) 8616-8639.        
 
[4] N.A. Zimbovskaya, The effect of dephasing on the thermoelectric efficiency of molecular junctions, Journal of Physics: Condensed Matter 26 (2014) 275303.                                    
 
[5] D. Nozaki, H. Sevinçli, W. Li, R. Gutiérrez, G. Cuniberti, Engineering the figure of merit and thermopower in single-molecule devices connected to semiconducting electrodes, Physical Review B 81 (2010) 235406.                
 
[6] H. Rezania, A. Abdi, Thermal conductivity of disordered AA-stacked bilayer graphene in the presence of bias voltage, The European Physical Journal B 88 (2015) 173.
[7] H. Rezania, M. Yarmohammadi, Dynamical thermal conductivity of bilayer graphene in the presence of bias voltage, Physica E: Low-dimensional Systems and Nanostructures 75 (2016) 125-135.                                                   
 
[8] H. Rezania, A.V. Ghorlivand, Seebeck coefficient and thermal conductivity of doped armchair graphene nanoribbon in the presence of magnetic field, Materials Research Bulletin 9(2018)18-22.                                                       
 
[9] H. Rezania, F. Azizi, The effects of transverse magnetic field and local electronic interaction on thermoelectric properties of monolayer graphene, Solid State Communications 27 (2018)65-71.                      
 
[10] M. Saito, Y. Miyamoto, Theoretical identification of the smallest fullerene, C20, Physical review letters 87 (2001) 035503.          
 
[11] E. Malolepsza, H.A. Witek, S. Irle, Comparison of geometric, electronic, and vibrational properties for isomers of small fullerenes C20-C36, The Journal of Physical Chemistry A 111 (2007) 6649-6657.                   
 
[12] M. Alcamí, G. Sánchez, S. Díaz-Tendero, Y. Wang, F. Martín, Structural patterns in fullerenes showing adjacent pentagons: C20 to C72, Journal of nanoscience and nanotechnology 7 (2007) 1329-1338.                 
 
[13] J.M. Soler, E. Artacho, J.D. Gale, A. García, J. Junquera, P. Ordejón, D. Sánchez-Portal, The SIESTA method for ab initio Order-N materials simulation, Journal of Physics: Condensed Matter 14 (2002) 2745.                     
 
[14] M. Brandbyge, J.L. Mozos, P. Ordejón, J. Taylor, K. Stokbro, Density-functional method for nonequilibrium electron transport, Physical Review B 65 (2002) 165401.
 
[15] H.J. Monkhorst, J.D. Pack, Special points for Brillouin-zone integrations, Physical review B 13 (1976) 5188.                                               
 
[16] G. Ji, D. Li, C. Fang, Y. Xu, Y. Zhai, B. Cui, D. Liu, Effect of contact interface configuration on electronic transport in (C20)2-based molecular junctions, Physics Letters A 376 (2012) 773-778.                                            
 
[17] S. Datta, Electronic transport in mesoscopic systems (Cambridge studies in semiconductor physics and microelectronic engineering), Cambridge University Press 40 (1997) 10011-4211.                                             
 
[18] C.M. Finch, V.M. Garcia-Suarez, C.J. Lambert, Giant thermopower and figure of merit in single-molecule devices, Physical review b 79 (2009) 033405.                                                
 
[19] Z. Golsanamlou, S.I. Vishkayi, M.B. Tagani, H.R. Soleimani, Thermoelectric properties of metal/molecule/metal junction for different lengths of polythiophene, Chemical Physics Letters 594 (2014) 51-57.                      
 
[20] A. Tan, J. Balachandran, S. Sadat, V. Gavini, B.D. Dunietz, S.Y. Jang, P. Reddy, Effect of length and contact chemistry on the electronic structure and thermoelectric properties of molecular junctions, Journal of the American Chemical Society 133 (2011) 8838-8841.   
 
[21] C. Evangeli, K. Gillemot, E. Leary, M.T. Gonzalez, G. Rubio-Bollinger, C.J. Lambert, N. Agraït, Engineering the thermopower of C60 molecular junctions, Nano letters 13 (2013) 2141-2145.                                                           
 
[22] J.C. Klöckner, R. Siebler, J.C. Cuevas, F. Pauly, Thermal conductance and thermoelectric figure of merit of C60-based single-molecule junctions: electrons, phonons, and photons, physical Review B 95 (2017) 245404.                  
 
[23] S.K. Lee, T. Ohto, R. Yamada, H. Tada, Thermopower of benzenedithiol and C60. molecular junctions with Ni and Au electrodes, Nano letters 14 (2014) 5276-5280.                      
 
[24] J.A. Malen, S.K. Yee, A. Majumdar, R.A. Segalman, Fundamentals of energy transport, energy conversion, and thermal properties in organic–inorganic heterojunctions, Chemical Physics Letters 491 (2010) 109-122.                   
 
[25] J.R. Widawsky, P. Darancet, J.B. Neaton, L. Venkataraman, Simultaneous determination of conductance and thermopower of single molecule junctions, Nano letters 12 (2011) 354-358.                                                                     
 
[26] S. Guo, G. Zhou, N. Tao, Single molecule conductance, thermopower, and transition voltage, Nano letters 13 (2013) 4326-4332.