Theoretical Study on Charge Transport Properties of Copolymers of Diketopyrrolopyrrole and Oligo-thiophene†

doi:10.7503/cjcu20170321

Abstract

Abstract:

The electronic structures and charge transport properties of the oligomers of diketopyrrolopyrrole(DPP) with the thiophene were investigated with ab initio density functional theory and classical Marcus charge transport theory. The results show that with the increase of the DPP concentration(or decrease of the thiophene numbers) in the polymer unit both the HOMO and LUMO energy levels of the polymers decrease, and the band gaps narrow. As the DPP concentration increased, the intrachain overlap of the electron wave functions of the DPP acceptor units was improved, that facilitates the intrachain electron transport. Moreover, the increase of DPP concentration strengthens the rigidity of the molecular backbone and enhances the interchain overlap of LUMO orbitals, which strengthens the electron transfer integrals and the system is converted from p-type into ambipolar materials.

Key words: Charge transport, Mobility, Ambipolar transport material, Diketopyrrolopyrrole(DPP), Oligothiophene

CLC Number:

O641

TrendMD:

FAN Jianxun, JI Lifei, REN Aimin. Theoretical Study on Charge Transport Properties of Copolymers of Diketopyrrolopyrrole and Oligo-thiophene^†[J]. Chem. J. Chinese Universities, 2017, 38(11): 2053.

Figures/Tables 9

Fig.1 Several DPP-containing building blocks for DPP-based conjugated polymers R is a suitable substituent, mostly an alkyl.

Fig.2 Chemical structure of PDPP-nT polymers

Fig.3 Calculated HOMO/LUMO energies for PDPP-nT at B3LYP-D3(BJ)/6-31G(d,p) level

Table 1 Calculated HOMO and LUMO levels and energy gaps at B3LYP-D3(BJ)/6-31G(d,p) level

Copolymer	Energy	m=1	m=2	m=3	m=4	m=∞	Exp.
PDPP-2T	E_HOMO/eV	-4.97	-4.82	-4.76	-4.73	-4.67	-5.40^[12]
	E_LUMO/eV	-2.51	-2.98	-3.15	-3.24	-3.47	-4.20^[12]
	E_g/eV	2.46	1.84	1.61	1.49	1.20	1.20
PDPP-3T	E_HOMO/eV	-4.86	-4.74	-4.70	-4.68	-4.62	-5.30^[15]
	E_LUMO/eV	-2.60	-2.94	-3.06	-3.12	-3.29	-4.00^[15]
	E_g/eV	2.26	1.80	1.64	1.56	1.33	1.30
PDPP-4T	E_HOMO/eV	-4.81	-4.70	-4.67	-4.66	-4.60	-5.20^[15]
	E_LUMO/eV	-2.65	-2.91	-3.01	-3.05	-3.18	-4.00^[16]
	E_g/eV	2.16	1.79	1.66	1.61	1.42	1.20
PDPP-5T	E_HOMO/eV	-4.78	-4.67	-4.65	-4.64	-4.59	-5.12^[17]
	E_LUMO/eV	-2.68	-2.89	-2.96	-2.99	-3.10	-3.55^[17]
	E_g/eV	2.10	1.78	1.69	1.65	1.49	1.57
PDPP-6T	E_HOMO/eV	-4.76	-4.65	-4.64	-4.63	-4.58	-5.10^[18]
	E_LUMO/eV	-2.70	-2.88	-2.93	-2.96	-3.05	-3.40^[18]
	E_g/eV	2.06	1.77	1.71	1.67	1.55	1.70

Fig.4 Top-view of the energy-minimized structure of trimers investigated by the B3LYP-D3(BJ)/6-31G(d,p) method with a visualization of the LUMO and HOMO molecular orbitals

Fig.5 Orbital energies changing with the number of (DPP-nT)3(n=2—6) trimers

Fig.6 Reorganization energies[hole(A)/electron(B)] changing with the degree of polymerization

Fig.7 Interaction energies(A1—E1) and the hole(A2—E2) and electron(A3—E3) transfer integrals for (DPP-nT)3 dimers as a function of the long-axis shifts and short-axis shifts with an interplanar distance of 0.365 nm(A1)—(A3) (DPP-2T)3; (B1)—(B3) (DPP-3T)3; (C1)—(C3) (DPP-4T)3; (D1)—(D3) (DPP-5T)3;(E1)—(E3) (DPP-6T)3. Each scanning step is set to be 0.05 nm.

Table 2 Summary of the hole and electron reorganization energies(λh/λe), the hole and electron transfer integrals(Vh/Ve) and the hole and electron mobilities(μe/μh) based on the one-dimensional π-stacking model

Compound	r/nm	λ_h/eV	λ_e/eV	V_h/eV	V_e/eV	μ_h/ (cm²·V^-1·s^-1)	μ_e/ (cm²·V^-1·s^-1)	μ_e/μ_h
(DPP-2T)₃	0.499	0.187	0.169	0.001	0.100	0.0005	3.787	7136.3
(DPP-3T)₃	0.473	0.151	0.135	0.059	0.057	1.515	1.709	1.13
(DPP-4T)₃	0.469	0.122	0.102	0.064	0.065	2.548	3.544	1.39
(DPP-5T)₃	0.403	0.102	0.077	0.098	0.016	5.888	0.237	0.04
(DPP-6T)₃	0.405	0.090	0.066	0.104	0.014	8.072	0.216	0.03

References 27

[1]	Tsumura A., Koezuka H., Ando T., Appl. Phys. Lett., 1986, 49(18), 1210-1212
[2]	Virkar A. A., Mannsfeld S., Bao Z., Stingelin N., Adv. Mater., 2010, 22(34), 3857-3875
[3]	Qu S. Y., Tian H., Chem. Commun., 2012, 48(25), 3039-3051
[4]	Biniek L., Schroeder B. C., Nielsen C. B., McCulloch I., J. Mater. Chem., 2012, 22(30), 14803-14813
[5]	Nielsen C. B., Turbiez M., McCulloch I., Adv. Mater., 2013, 25(13), 1859-1880
[6]	Li Y. N., Sonar P., Murphy L., Hong W., Energy Environ. Sci., 2013, 6(6), 1684-1710
[7]	Zhao Y., Guo Y. L., Liu Y. Q., Adv. Mater., 2013, 25(38), 5372-5391
[8]	Turbiez M. G., Janssen R. A. J., Wienk M. M., Kirner H. J., Düggeli M., Tieke B., Zhu Y., Diketopyrrolopyrrole Polymers as Organic Semiconductors, WO 2008000664,2008-01-03
[9]	Wienk M. M., Turbiez M., Gilot J., Janssen R. A. J., Adv. Mater., 2008, 20(13), 2556-2560
[10]	Burgi L., Turbiez M., Pfeiffer R., Bienewald F., Kirner H. J., Winnewisser C., Adv. Mater., 2008, 20(11), 2217-2224
[11]	Zoombelt A. P., Mathijssen S. G. J., Turbiez M. G. R., Wienk M. M., Janssen R. A. J., J. Mater. Chem., 2010, 20(11), 2240-2246
[12]	Li Y. N., Sun B., Sonar P., Singh S. P., Org. Electron., 2012, 13(9), 1606-1613
[13]	Kanimozhi C., Yaacobi-Gross N., Chou K. W., Amassian A., Anthopoulos T. D., Patil S., J. Am. Chem. Soc., 2012, 134(40), 16532-16535
[14]	Bijleveld J. C., Zoombelt A. P., Mathijssen S. G. J., Wienk M. M., Turbiez M., de Leeuw D. M., Janssen R. A. J., J. Am. Chem. Soc., 2009, 131(46), 16616-16617
[15]	Lee J. S., Son S. K., Song S., Kim H., Lee D. R., Kim K., Ko M. J., Choi D. H., Kim B., Cho J. H., Chem. Mater., 2012, 24(7), 1316-1323
[16]	Li Y. N., Sonar P., Singh S. P., Soh M. S., van Meurs M., Tan J., J. Am. Chem. Soc., 2011, 133(7), 2198-2204
[17]	Yi Z. R., Sun X. N., Zhao Y., Guo Y. L., Chen X. G., Qin J. G., Yu G., Liu Y. Q., Chem. Mater., 2012, 24(22), 4350-4356
[18]	Yi Z. R., Ma L. C., Chen B., Chen D. G., Chen X. G., Qin J. G., Zhan X. W., Liu Y. Q., Ong W. J., Li J., Chem. Mater., 2013, 25(21), 4290-4296
[19]	Shahid M., McCarthy-Ward T., Labram J., Rossbauer S., Domingo E. B., Watkins S. E., Stingelin N., Anthopoulos T. D., Heeney M., Chem. Sci., 2012, 3(1), 181-185
[20]	Marcus R. A., Rev. Mod. Phys., 1993, 65(3), 599-610
[21]	Schein L. B., McGhie A. R., Chem. J. Chinese Universities,2010, 31(4), 1631-1639
[22]	Te Velde G., Bickelhaupt F. M., Baerends E. J., Fonseca Guerra C., van Gisbergen S. J. A., Snijders J. G., Ziegler T., J. Comput. Chem., 2001, 22(9), 931-967
[23]	Frisch M.J., Trucks G. W., Schlegel H. B., Scuseria G. E., Robb M. A., Cheeseman J. R., Scalmani G., Barone V., Mennucci B., Petersson G. A., Nakatsuji H., Caricato M., Li X., Hratchian H. P., Izmaylov A. F., Bloino J., Zheng G., Sonnenberg J. L., Hada M., Ehara M., Toyota K., Fukuda R., Hasegawa J., Ishida M., Nakajima T., Honda Y., Kitao O., Nakai H., Vreven T., Montgomery J. A., Peralta J. E., Ogliaro F., Bearpark M., Heyd J. J., Brothers E., Kudin K. N., Staroverov V. N., Kobayashi R., Normand J., Raghavachari K., Rendell A., Burant J. C., Iyengar S. S., Tomasi J., Cossi M., Rega N., Millam J. M., Klene M., Knox J. E., Cross J. B., Bakken V., Adamo C., Jaramillo J., Gomperts R., Stratmann R. E., Yazyev O., Austin A. J., Cammi R., Pomelli C., Ochterski J. W., Martin R. L., Morokuma K., Zakrzewski V. G., Voth G. A., Salvador P., Dannenberg J. J., Dapprich S., Daniels A. D., Farkas Ö., Foresman J. B., Ortiz J. V., Cioslowski J., Fox D. J., Gaussian 09, Revision E.01, Gaussian Inc., Wallingford CT, 2013
[24]	Yi Z. R., Wang S., Liu Y. Q., Adv. Mater., 2015, 27(24), 3589-3606
[25]	Yun H. J., Choi H. H., Kwon S. K., Kim Y. H., Cho K., Chem. Mater., 2014, 26(13), 3928-3937
[26]	Kanimozhi C., Yaacobi-Gross N., Burnett E. K., Briseno A. L., Anthopoulos T. D., Salzner U., Patil S., Phys. Chem. Chem. Phys., 2014, 16(32), 17253-17265
[27]	Coropceanu V., Cornil J., da Silva D. A., Olivier Y., Silbey R., Bredas J. L., Chem. Rev., 2007, 107(4), 926-952