TY - JOUR
T1 - Regio-regular alternating diketopyrrolopyrrole-based D1-A-D2-A terpolymers for the enhanced performance of polymer solar cells
AU - Lee, Myeongjae
AU - Kim, Taehyo
AU - Nguyen, Hoai Van T.
AU - Cho, Hye Won
AU - Lee, Kyung Koo
AU - Choi, Jong Ho
AU - Kim, Bongsoo
AU - Kim, Jin Young
N1 - Funding Information:
This work was supported by the National Research Foundation (NRF-2018R1A5A1025594, 2015M1A2A2056218) of the Ministry of Science and ICT, by the New Renewable Energy Core Technology Development Project of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) granted nancial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20183010013900), and also by a grant from the R&D Convergence Program of NST (National Research Council of Science & Technology) of Republic of Korea (CAP-15-04-KITECH).
Publisher Copyright:
© 2019 The Royal Society of Chemistry.
PY - 2019
Y1 - 2019
N2 - We designed and synthesized regio-regular alternating diketopyrrolopyrrole (DPP)-based D1-A-D2-A terpolymers (PDPPF2T2DPP-T2, PDPPF2T2DPP-TVT, and PDPPF2T2DPP-DTT) using a primary donor (D1) [3,3′-difluoro-2,2′-bithiophene (F2T2)] and a secondary donor (D2) [2,2′-bithiophene (T2), (E)-1,2-di(thiophen-2-yl)ethene (TVT), or dithieno[3,2-b:2′,3′-d]thiophene (DTT)]. A PDPP2DT-F2T2 D-A polymer was synthesized as well to compare optical, electronic, and photovoltaic properties. The absorption peaks of the terpolymers (PDPPF2T2DPP-T2, PDPPF2T2DPP-TVT, and PDPPF2T2DPP-DTT) were longer (λmax = 801-810 nm) than the peak of the PDPP2DT-F2T2 polymer (λmax = 799 nm), which is associated with the high-lying HOMO levels of the terpolymers (-5.08 to -5.13 eV) compared with the level of the PDPP2DT-F2T2 polymer (-5.38 eV). The photovoltaic properties of these DPP-based polymers were investigated under simulated AM 1.5G sunlight (100 mW cm-2) with a conventional structure (ITO/PEDOT:PSS/polymer:PC71BM/Al). The open-circuit voltages (Voc) of photovoltaic devices containing the terpolymers were slightly lower (0.68-0.70 V) than the Voc of the device containing the PDPP2DT-F2T2 polymer (0.79 V). The short-circuit current (Jsc) of the PDPPF2T2DPP-DTT device was significantly improved (14.14 mA cm-2) compared with that of the PDPP2DT-F2T2 device (8.29 mA cm-2). As a result, the power conversion efficiency (PCE) of the PDPPF2T2DPP-DTT device (6.35%) was increased by 33% compared with that of the simple D-A-type PDPP2DT-F2T2 device (4.78%). The highest Jsc and PCE values (the PDPPF2T2DPP-DTT device) were attributed to an optimal nanoscopically mixed morphology and strong interchain packing with a high face-on orientation in the blend film state. The study demonstrated that our strategy of using multiple donors in a regio-regular alternating fashion could fine-tune the optical, electronic, and morphological properties of D-A-type polymers, enhancing the performance of polymer solar cells.
AB - We designed and synthesized regio-regular alternating diketopyrrolopyrrole (DPP)-based D1-A-D2-A terpolymers (PDPPF2T2DPP-T2, PDPPF2T2DPP-TVT, and PDPPF2T2DPP-DTT) using a primary donor (D1) [3,3′-difluoro-2,2′-bithiophene (F2T2)] and a secondary donor (D2) [2,2′-bithiophene (T2), (E)-1,2-di(thiophen-2-yl)ethene (TVT), or dithieno[3,2-b:2′,3′-d]thiophene (DTT)]. A PDPP2DT-F2T2 D-A polymer was synthesized as well to compare optical, electronic, and photovoltaic properties. The absorption peaks of the terpolymers (PDPPF2T2DPP-T2, PDPPF2T2DPP-TVT, and PDPPF2T2DPP-DTT) were longer (λmax = 801-810 nm) than the peak of the PDPP2DT-F2T2 polymer (λmax = 799 nm), which is associated with the high-lying HOMO levels of the terpolymers (-5.08 to -5.13 eV) compared with the level of the PDPP2DT-F2T2 polymer (-5.38 eV). The photovoltaic properties of these DPP-based polymers were investigated under simulated AM 1.5G sunlight (100 mW cm-2) with a conventional structure (ITO/PEDOT:PSS/polymer:PC71BM/Al). The open-circuit voltages (Voc) of photovoltaic devices containing the terpolymers were slightly lower (0.68-0.70 V) than the Voc of the device containing the PDPP2DT-F2T2 polymer (0.79 V). The short-circuit current (Jsc) of the PDPPF2T2DPP-DTT device was significantly improved (14.14 mA cm-2) compared with that of the PDPP2DT-F2T2 device (8.29 mA cm-2). As a result, the power conversion efficiency (PCE) of the PDPPF2T2DPP-DTT device (6.35%) was increased by 33% compared with that of the simple D-A-type PDPP2DT-F2T2 device (4.78%). The highest Jsc and PCE values (the PDPPF2T2DPP-DTT device) were attributed to an optimal nanoscopically mixed morphology and strong interchain packing with a high face-on orientation in the blend film state. The study demonstrated that our strategy of using multiple donors in a regio-regular alternating fashion could fine-tune the optical, electronic, and morphological properties of D-A-type polymers, enhancing the performance of polymer solar cells.
UR - http://www.scopus.com/inward/record.url?scp=85077322200&partnerID=8YFLogxK
U2 - 10.1039/c9ra08858j
DO - 10.1039/c9ra08858j
M3 - Article
AN - SCOPUS:85077322200
VL - 9
SP - 42096
EP - 42109
JO - RSC Advances
JF - RSC Advances
SN - 2046-2069
IS - 72
ER -
