Controlling molecular weight of naphthalenediimide-based polymer acceptor P(NDI2OD-T2) for high performance all-polymer solar cells

doi:10.1016/j.jmst.2016.06.028

Abstract

Abstract:

A widely-used naphthalenediimide (NDI) based electron acceptor P(NDI2OD-T2) with different number-average molecular weight (M_n) of 38 (N2200_L), 56 (N2200_M), 102 (N2200_H) kDa were successfully prepared. The effect of molecular-weight on the performance of all-polymer solar cells based on Poly(5-(5-(4,8-bis(5-decylthiophen-2-yl)-6-methylbenzo[1,2-b:4,5-b’]dithophen-2-yl)thiophen-2-yl)-6,7-difluoro-8-(5-methylthiophen-2-yl)-2,3-bis(3-(octyloxy)phenyl)quinoxaline) (P2F-DE):N2200 was systematically investigated. The results reveal that N2200 with increased M_n show enhanced intermolecular interactions, resulting in improved light absorption and electron mobility. However, the strong aggregation trend of N2200_H can cause unfavorable morphology for exciton dissociation and carrier transport. The blend film using N2200 with moderate M_n actually develops more ideal phase segregation for efficient charge separation and transport, leading to balanced electron/hole mobility and less carrier recombination. Consequently, all-polymer solar cells employing P2F-DE as the electron donor and N2200_M as the electron acceptor show the highest efficiency of 4.81%, outperforming those using N2200_L (3.07%) and N2200_H (3.92%). Thus, the M_n of the polymer acceptor plays an important role in all-polymer solar cells, which allows it to be an effective parameter for the adjustment of the device morphology and efficiency.

Key words: All-polymer solar cells, Polymer acceptor, Molecular weight, Aggregation, Blend morphology

Lei Yu, Sun Jianxia, Yuan Jianyu, Gu Jinan, Ding Guanqun, Ma Wanli. Controlling molecular weight of naphthalenediimide-based polymer acceptor P(NDI2OD-T2) for high performance all-polymer solar cells[J]. J. Mater. Sci. Technol., 2017, 33(5): 411-417.

Figures/Tables 10

Scheme 1. Preparation of polymer P2F-DE and N2200 with different molecular weights.

Table 1 Molecular weights and properties of N2200 polymers.

Polymer	M_n (kDa)	PDI	film λ_max (nm)	E_g^opt (eV)
N2200_L	38	2.14	694	1.49
N2200_M	56	1.83	694	1.46
N2200_H	102	1.61	697	1.46

Fig. 1. Normalized UV-vis absorption spectra of donor and acceptor polymers films spin-cast from chloroform solutions.

Fig. 2. Current density-voltage (J-V) (a) and EQE (b) curves of optimized all-PSCs based on P2F-DE:N2200 with different molecular weights.

Table 2 Photovoltaic properties of all-PSCs using P2F-DE as donor and N2200 as acceptor, under the illumination of AM1.5G, 100 mW cm-2.

Polymer	V_oc(V)	J_sc (mA cm^-2)	FF (%)	PCE_max (%)	PCE_av (%)^a
N2200_L	0.73	9.46	44.8	3.07	2.89
N2200_M	0.76	11.72	54.1	4.81	4.67
N2200_H	0.75	10.34	50.5	3.92	3.85

Table 3 Summary of SCLC mobilities for pristine and blend polymer filmsa.

	Hole (cm² V^-1 s^-1)	Electron (cm² V^-1 s^-1)	Hole/Electron
P2F-DE:N2200_L	5.1 × 10^-4	5.9 × 10^-5	8.6
P2F-DE:N2200_M	2.4 × 10^-4	5.3 × 10^-4	2.2
P2F-DE:N2200_H	1.9 × 10^-4	7.7 × 10^-4	4.1
Neat P2F-DE	2.2 × 10^-4	-	-
Neat N2200_L	-	3.1 × 10^-4	-
Neat N2200_M	-	6.3 × 10^-4	-
Neat N2200_H	-	1.1 × 10^-3	-

Fig. 3. Light intensity dependence of Jsc (a) and Voc (b) of all-polymer solar cell devices based on N2200 with different molecular weights.

Fig. 4. AFM height images of P2F-DE:N2200 blends with different molecular weights (5.0 μm × 5.0 μm, RMS: root mean square roughness): (a) P2F-DE:N2200L; (b) P2F-DE:N2200M; (c) P2F-DE:N2200H.

Fig. 5. TEM images of P2F-DE:N2200 blends with different molecular weights: (a) P2F-DE:N2200L; (b) P2F-DE:N2200M; (c) P2F-DE:N2200H.

Fig. 6. Temperature-dependent UV-vis absorption spectra of N2200 polymers in ODCB with a concentration of 0.01 mg/mL: (a) P2F-DE:N2200L; (b) P2F-DE:N2200M; (c) P2F-DE:N2200H.Figure options

References

[1]	C.J. Brabec, S. Gowrisanker, J.J. Halls, D. Laird, S. Jia, S.P. Williams, Adv. Mater.22(2010) 3839-3856.
[2]	M.T. Dang, L. Hirsch, G.Wantz, J.D.Wuest, Chem. Rev. 113(2013) 3734-3765.
[3]	Y. Liu, J. Zhao, Z. Li, C. Mu, W. Ma, H. Hu, K. Jiang, H. Lin, H. Ade, H. Yan, Nat.Commun. 5(2014) 5293-5301.
[4]	C.C. Chen, W.H. Chang, K. Yoshimura, K. Ohya, J. You, J. Gao, Z. Hong, Y. Yang,Adv. Mater. 26(2014) 5670-5677.
[5]	Z. He, B. Xiao, F. Liu, H. Wu, Y. Yang, S. Xiao, C. Wang, T.P. Russell, Y. Cao, Nat.Photonics 9 (2015) 174-179.
[6]	Z. Zheng, S. Zhang, J. Zhang, Y. Qin, W. Li, R. Yu, Z. Wei, J. Hou, Adv. Mater. 28(2016) 5133-5138.
[7]	J. Zhao, Y. Li, G. Yang, K. Jiang, H. Lin, H. Ade, W. Ma, Y. He, Nat. Energy 1 (2)(2016) 15027-.
[8]	P.A. Troshin, H. Hoppe, J. Renz, M. Egginger, J.Y. Mayorova, A.E. Goryachev, A.S.Peregudov, R.N. Lyubovskaya, G. Gobsch, N.S. Sariciftci, V.F. Razumov, Adv. Funct.Mater. 19(2009) 779-788.
[9]	W. Zhao, D. Qian, S. Zhang, S. Li, O. Ingan?s, F. Gao, J. Hou, Adv. Mater. 28(2016)4734-4739.
[10]	Y. Lin, F. Zhao, Q. He, L. Huo, Y.Wu, T.C. Parker,W. Ma, Y. Sun, C.Wang, D. Zhu,A.J. Heege, S.R. Marder, X. Zhan, J. Am. Chem.Soc. 138(2016) 4955-4961.
[11]	Y. He, Y. Li, Phys. Chem. Chem.Phys. 13(2011) 1970-1983.
[12]	J. Zhao, Y. Li, H. Lin, Y. Liu, K. Jiang, C. Mu, T. Ma, J.Y.L.Lai, H. Hu,D. Yu, H. Yan,Energy Environ. Sci. 8(2015) 520-525.
[13]	E. Ahmed, G. Ren, F.S. Kim, E.C. Hollenbeck, S.A. Jenekhe, Chem. Mater. 23(2011)4563-4577.
[14]	D. Mori, H. Benten, I. Okada, H. Ohkita, S. Ito, Energy Environ.Sci. 7(2014)2939-2943.
[15]	C. Lee, H. Kang,W. Lee, T. Kim, K.H. Kim, H.Y.Woo, C.Wang, B.J. Kim, Adv. Mater.27(2015) 2466-2471.
[16]	A. Facchetti, Mater. Today 16 (2013) 123-132.
[17]	H. Benten, D. Mori, H. Ohkita, S. Ito, J.Mater Chem. A 4(2016) 5340-5365.
[18]	J.R. Moore, S. Albert-Seifried, A. Rao, S. Massip, B.Watts, D.J. Morgan, R.H. Friend,C.R.McNeill,H. Sirringhaus, Adv. Energy Mater. 1(2011) 230-240.
[19]	L. Gao, Z.G. Zhang, L. Xue, J. Min, J. Zhang, Z. Wei, Y. Li, Adv. Mater. 28(2015)1884-1890.
[20]	J.W. Jung, J.W. Jo, C.C. Chueh, F. Liu, W.H. Jo, T.P. Russell, A.K.Y.Jen, Adv. Mater.27(2015) 3310-3317.
[21]	Y.J. Hwang, T. Earmme, B.A. Courtright, F.N. Eberle, S.A. Jenekhe, J. Am. Chem.Soc. 137(2015) 4424-4434.
[22]	Y.J. Hwang, B.A. Courtright, A.S. Ferreira, S.H. Tolbert, S.A. Jenekhe, Adv. Mater.27(2015) 4578-4584.
[23]	T. Earmme, Y.J. Hwang, S. Subramaniyan, S.A. Jenekhe, Adv. Mater. 26(2014)6080-6085.
[24]	T. Earmme, Y.J. Hwang, N.M. Murari, S. Subramaniyan, S.A. Jenekhe, J. Am. Chem.Soc. 135(2013) 14960-14963.
[25]	W. Ma, J.Y. Kim, K. Lee, A.J. Heeger, Macromol. Rapid Commun. 28(2007)1776-1780.
[26]	C. Müller, E. Wang, L.M. Andersson, K. Tvingstedt, Y. Zhou, M.R. Andersson, O.Ingan?s, Adv. Funct. Mater. 20(2010) 2124-2131.
[27]	T.Y. Chu, J. Lu, S. Beaupré, Y. Zhang, J.R. Pouliot, J. Zhou, A. Najari, M. Leclerc, Y.Tao, Adv. Funct. Mater. 22(2012) 2345-2351.
[28]	C. Liu, K.Wang, X. Hu, Y. Yang, C.H. Hsu,W. Zhang, S. Xiao, X. Gong, Y. Cao, ACS Appl. Mater. Interf. 5(2013) 12163-12167.
[29]	R. Matsidik, H. Komber, A. Luzio, M. Caironi, M. Sommer, J. Am. Chem.Soc. 137(2015) 6705-6711.
[30]	F. Liu, D. Chen, C. Wang, K. Luo, W. Gu, A.L. Briseno, J.W. Hsu, T.P. Russell, ACS Appl. Mater. Interf. 6(2014) 19876-19887.
[31]	D. Mori, H. Benten, H. Ohkita, S. Ito, K. Miyake, ACS Appl. Mater. Interf. 4(2012) 3325-3329.
[32]	H. Kang, M.A. Uddin, C. Lee, K.H. Kim, T.L. Nguyen, W. Lee, Y. Li, C. Wang, H.Y. Woo, B.J. Kim, J. Am. Chem.Soc. 137(2015) 2359-2365.
[33]	N. Zhou, A.S. Dudnik, T.I. Li, E.F. Manley, T.J. Aldrich, P. Guo, H.C. Liao, Z. Chen, L.X. Chen, R.P. Chang, A. Facchetti, M. Olvera de la Cruz,T.J. Marks, J. Am. Chem.Soc. 138(2016) 1240-1251.
[34]	J. Yuan, Z. Zhai, H. Dong, J. Li, Z. Jiang, Y. Li,W. Ma, Adv. Funct. Mater. 23(2013)885-892.
[35]	J. Sun, J. Gu, J. Yuan, Z. Cui, K. Lu, S. Shi, G. Ding,W. Ma, Org. Electron. 33(2016)227-234.
[36]	J. Yuan,W. Ma, J. Mater. Chem. A 3 (2015) 7077-7085.
[37]	S. Fabiano, S. Himmelberger, M. Drees, Z. Chen, R.M. Altamimi, A. Salleo, M.A.Loi, A. Facchetti, Adv. Energy Mater. 4(2014) 1301409.
[38]	J. Yuan, X. Huang, F. Zhang, J. Lu, Z. Zhai, C. Di, Z. Jiang, W. Ma, J. Mater.Chem.22(2012) 22734-22742.
[39]	R. Steyrleuthner, R. Di Pietro, B.A. Collins, F. Polzer, S. Himmelberger, M.Schubert, Z. Chen, S. Zhang, A. Salleo, H. Ade, A. Facchetti, D. Neher, J. Am.Chem.Soc. 136(2014) 4245-4256.
[40]	Y. Zhong, M.T. Trinh, R. Chen,W.Wang, P.P. Khlyabich, B. Kumar, Q. Xu, C.Y. Nam,M.Y. Sfeir, C. Black, M.L. Steigerwald, Y.L. Loo, S. Xiao, F. Ng, X.Y. Zhu, C. Nuckolls,J. Am.Chem.Soc. 136(2014) 15215-15221.
[41]	L.J. Koster, M. Kemerink, M.M. Wienk, K. Maturova, R.A. Janssen, Adv. Mater.23(2011) 1670-1674.
[42]	S.R. Cowan, A. Roy, A.J. Heeger, Phys. Rev. B 82 (2010) 245207.
[43]	S. Venkatesan, N. Adhikari, J. Chen, E.C. Ngo, A. Dubey, D.W. Galipeau, Q. Qiao,Nanoscale 6 (2014) 1011-1019.
[44]	X. Guo, M. Zhang, W. Ma, L. Ye, S. Zhang, S. Liu, H. Ade, F. Huang, J. Hou, Adv.Mater. 26(2014) 4043-4049.
[45]	D. Mori, H. Benten, J. Kosaka, H. Ohkita, S. Ito, K. Miyake, ACS Appl. Mater. Interf.3(2011) 2924-2927.
[46]	Y.J. Hwang, T. Earmme, B.A. Courtright, F.N. Eberle, S.A. Jenekhe, J. Am. Chem.Soc. 137(2015) 4424-4434.
[47]	R. Steyrleuthner, M. Schubert, I. Howard, B. Klaumunzer, K. Schilling, Z. Chen,P. Saalfrank, F. Laquai, A. Facchetti, D. Neher, J. Am.Chem.Soc. 134(2012)18303-18317.
[48]	M. Schubert, D. Dolfen, J. Frisch, S. Roland, R. Steyrleuthner, B. Stiller, Z. Chen,U. Scherf, N. Koch, A. Facchetti, D. Neher, Adv. Energy Mater. 2(2012) 369-380.