Efficient and Stable Ternary Organic Solar Cells ... - ACS Publications

Jun 1, 2017 - Department of Materials Science, Fudan University, Shanghai 200433, China .... light absorption and suitable energy levels with planar P...
1 downloads 0 Views 2MB Size
Article

Efficient and Stable Ternary Organic Solar Cells Based on Two Planar Nonfullerene Acceptors with Tunable Crystallinity and Phase Miscibility Jialin Wang, Jiajun Peng, Xiaoyu Liu, and Ziqi Liang ACS Appl. Mater. Interfaces, Just Accepted Manuscript • Publication Date (Web): 01 Jun 2017 Downloaded from http://pubs.acs.org on June 1, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

ACS Applied Materials & Interfaces is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 24

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

Efficient and Stable Ternary Organic Solar Cells Based on Two Planar Nonfullerene Acceptors with Tunable Crystallinity and Phase Miscibility Jialin Wang, Jiajun Peng, Xiaoyu Liu and Ziqi Liang* Department of Materials Science, Fudan University, Shanghai 200433, China

ABSTRACT: Planar perylene diimides (PDI), when used as nonfullerene acceptors for organic photovoltaics, are constrained by their large π-aggregation in solid state. To tackle this issue, another planar nonfullerene acceptor 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone)5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indaceno[1,2-b:5,6-b']dithiophene (ITIC) with weak crystallinity and near-infrared light absorption is introduced into the PTB7Th:PDI binary blend to fabricate efficient and stable ternary solar cells. We have finely tuned the PDI/ITIC weight ratio to investigate the influences of individual ITIC and PDI on the optical, electronic and morphological properties of PTB7-Th:ITIC:PDI ternary blend. Compared to the binary blend, complementary optical absorption is achieved in all ternary blends. More importantly, it is found that ITIC plays a critical role on largely suppressing the PDI aggregates in PTB7-Th:PDI blend, while PDI aids to form an interpenetrating network morphology to facilitate charge transport in PTB7-Th:ITIC blend. Consequently, when the PDI/ITIC ratio is 3:7 (w/w), the PTB7-Th:ITIC:PDI based inverted solar cells exhibit the highest power conversion

1 Environment ACS Paragon Plus

ACS Applied Materials & Interfaces

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

efficiency of 8.64% due to their favorable out-of-plane π-π stacking, finest phase-separation morphology and highest charge mobility. Remarkably, the optimal cells that are solutionprocessed in air show the promising efficiency of 7.09%, suggesting good ambient stability of such ternary solar cells. KEYWORDS: ternary organic solar cells, planar perylene diimide, aggregation, phase miscibility, air stability

1. INTRODUCTION Perylene diimides (PDIs) are considered as potential alternatives to fullerene based acceptors in organic solar cells (OSCs) owing to their high electron affinity similar to fullerene derivatives, large optical extinction coefficients, high electron mobilities and great photochemical stability.1–4 However, their applications for bulk-heterojunction (BHJ) OSCs are now largely staggered by the strong π-aggregation in solid state, especially in planar PDIs molecules, which may form unfavorable blend film morphology with submicrometer-scale PDI domains and thus result in the excimer and incomplete exciton dissociation.5–7 To date, planar PDI-based OSCs have utilized paradigm donor polymers such as poly(3-hexylthiophene) (P3HT),8,9 poly({4,8-bis[(2ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)-carbonyl]thieno[3,4-b]thiophenediyl}) (PTB7),10 pseudo-two-dimensional (2D) conjugated polymers with alkylthienyl side chains such as PBDTTT-C-T,11 along with small molecule donor.12 Most of them exhibited low power conversion efficiency (PCE) of less than 4% with short-circuit current density (JSC) 10%. Adv. Mater. 2016, 28, 10008– 10015. (29) Qin, Y.; Uddin, M. A.; Chen, Y.; Jang, B.; Zhao, K.; Zheng, Z.; Yu, R.; Shin, T. J.; Woo, H. Y.; Hou, J. Highly Efficient Fullerene-Free Polymer Solar Cells Fabricated with Polythiophene Derivative. Adv. Mater. 2016, 28, 9416–9422. (30) Zhang, H.; Li, S.; Xu, B.; Yao, H.; Yang, B.; Hou, J. Fullerene-Free Polymer Solar Cell Based on a Polythiophene Derivative with an Unprecedented Energy Loss of Less Than 0.5 eV. J. Mater. Chem. A 2016, 4, 18043–18049. (31) Zheng, Z.; Awartani, O. M.; Gautam, B.; Liu, D.; Qin, Y.; Li, W.; Bataller, A.; Gundogdu, K.; Ade, H.; Hou, J. Efficient Charge Transfer and Fine-Tuned Energy Level Alignment in a THF-Processed Fullerene-Free Organic Solar Cell with 11.3% Efficiency. Adv. Mater. 2017, 29, 1604241.

22 Environment ACS Paragon Plus

Page 23 of 24

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

(32) Gupta, V.; Bharti, V.; Kumar, M.; Chand, S.; Heeger, A. J. Polymer–Polymer Förster Resonance Energy Transfer Significantly Boosts the Power Conversion Efficiency of BulkHeterojunction Solar Cells. Adv. Mater. 2015, 27, 4398–4404. (33) Bi, P.-Q.; Wu, B.; Zheng, F.; Xu, W.-L.; Yang, X.-Y.; Feng, L.; Zhu, F.; Hao, X.-T. An Obvious Improvement in the Performance of Ternary Organic Solar Cells with “Guest” Donor Present at the “Host” Donor/Acceptor Interface. ACS Appl. Mater. Interfaces 2016, 8, 23212– 23221. (34) Aluicio-Sarduy, E.; Singh, R.; Kan, Z.; Ye, T.; Baidak, A.; Calloni, A.; Berti, G.; Duò, L.; Iosifidis, A.; Beaupré, S.; Leclerc, M.; Butt, H.-J.; Floudas, G.; Keivanidis, P. E. Elucidating the Impact of Molecular Packing and Device Architecture on the Performance of Nanostructured Perylene Diimide Solar Cells. ACS Appl. Mater. Interfaces 2015, 7, 8687–8698. (35) Zhang, J.; Zhang, Y.; Fang, J.; Lu, K.; Wang, Z.; Ma, W.; Wei, Z., Conjugated PolymerSmall Molecule Alloy Leads to High Efficient Ternary Organic Solar Cells. J. Am. Chem. Soc. 2015, 137, 8176–8183. (36) Lin, Y.; Wang, J.; Zhang, Z.-G.; Bai, H.; Li, Y.; Zhu, D.; Zhan, X. An Electron Acceptor Challenging Fullerenes for Efficient Polymer Solar Cells. Adv. Mater. 2015, 27, 1170–1174. (37) Zheng, Z.; Awartani, O. M.; Gautam, B.; Liu, D.; Qin, Y.; Li, W.; Bataller, A.; Gundogdu, K.; Ade, H.; Hou, J. Efficient Charge Transfer and Fine-Tuned Energy Level Alignment in a THF-Processed Fullerene-Free Organic Solar Cell with 11.3% Efficiency. Adv. Mater. 2017, 29, 1604241. (38) Sun, D.; Meng, D.; Cai, Y.; Fan, B.; Li, Y.; Jiang, W.; Huo, L.; Sun, Y.; Wang, Z. NonFullerene-Acceptor-Based Bulk-Heterojunction Organic Solar Cells with Efficiency over 7%. J. Am. Chem. Soc. 2015, 137, 11156–11162.

23 Environment ACS Paragon Plus

ACS Applied Materials & Interfaces

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 24 of 24

(39) Wang, J.; Peng, J.; Sun, Y.; Liu, X.; Chen, Y.; Liang, Z. FAPbCl3 Perovskite as Alternative Interfacial Layer for Highly Efficient and Stable Polymer Solar Cells. Adv. Electron. Mater. 2016, 2, 1600329. (40) Shoaee, S.; Deledalle, F.; Tuladhar, P. S.; Shivanna, R.; Rajaram, S.; Narayan, K. S.; Durrant, J. R. A Comparison of Charge Separation Dynamics in Organic Blend Films Employing Fullerene and Perylene Diimide Electron Acceptors. J. Phys. Chem. Lett. 2015, 6, 201–205.

TOC GRAPHICS

Ternary blend cells based on two stable planar nonfullerene acceptors of PDI and ITIC with complementary optical absorption and crystallinity exhibit the PCEs of 8.64% and 7.09% in N2 and air, respectively.

24 Environment ACS Paragon Plus