Quinoxaline-Based Wide Band Gap Polymers for Efficient Nonfullerene Organic Solar Cells with Large Open-Circuit Voltages

Yang, Jie1,2; Uddin, Mohammad Afsar3; Tang, Yumin1,2; Wang, Yulun1,2; Wang, Yang1,2; Su, Huimin1,2; Gao, Rutian4; Chen, Zhi-Kuan4; Dai, Junfeng1,2; Woo, Han Young3; Guo, Xugang1,2

2018-07-11

10.1021/acsami.8b04432

ACS Applied Materials & Interfaces   影响因子和分区

1944-8244

1944-8252

We present here a series of wide-band-gap (E-g: >1.8 eV) polymer donors by incorporating thiophene-flanked phenylene as an electron-donating unit and quinoxaline as an electron-accepting co-unit to attain large open-circuit voltages (V(oc)s) and short-circuit currents (J(sc)s) in nonfullerene organic solar cells (OSCs). Fluorination was utilized to fine-tailor the energetics of polymer frontier molecular orbitals (FMOs) by replacing a variable number of H atoms on the phenylene moiety with F. It was found that fluorination can effectively modulate the polymer backbone planarity through intramolecular noncovalent S...F and/or H...F interactions. Polymers (P2-P4) show an improved molecular packing with a favorable face-on orientation compared to their nonfluorinated analogue (P1), which is critical to charge carrier transport and collection. When mixed with IDIC, a nonfullerene acceptor, P3 with two F atoms, achieves a remarkable V-oc of 1.00 V and a large J(sc) of 15.99 mA/cm(2), simultaneously, yielding a power-conversion efficiency (PCE) of 9.7%. Notably, the 1.00 V V-oc is among the largest values in the IDIC-based OSCs, leading to a small energy loss (E-loss: 0.62 eV) while maintaining a large PCE. The P3:IDIC blend shows an efficient exciton dissociation through hole transfer even under a small energy offset of 0.16 eV. Further fluorination leads to the polymer P4 with increased chain-twisting and mismatched FMO levels with IDIC, showing the lowest PCE of 2.93%. The results demonstrate that quinoxaline-based copolymers are promising donors for efficient OSCs and the fluorination needs to be fine-adjusted to optimize the interchain packing and physicochemical properties of polymers. Additionally, the structure property correlations from this work provide useful insights for developing wide-band-gap polymers with low-lying highest occupied molecular orbitals to minimize E-loss, and maximize V-oc in nonfullerene OSCs for efficient power conversion.

polymer semiconductors fluorination nonfullerene organic solar cells energy losses open-circuit voltages

SCI ; EI

英语

第一 ; 通讯

NRF of Korea[2015R1D1A1A09056905] ; NRF of Korea[20100020209]

Science & Technology - Other Topics ; Materials Science

Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary

WOS:000439007700039

AMER CHEMICAL SOC

20182605357177

Aromatic compounds ; Carrier transport ; Energy dissipation ; Energy gap ; Fluorination ; Fullerenes ; Halogenation ; Molecular orbitals ; Molecular orientation ; Open circuit voltage ; Organic polymers ; Organic solar cells ; Timing circuits

Energy Losses (industrial and residential):525.4 ; Electricity: Basic Concepts and Phenomena:701.1 ; Pulse Circuits:713.4 ; Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Organic Compounds:804.1 ; Organic Polymers:815.1.1 ; Mechanics:931.1

Web of Science

1.South Univ Sci & Technol China, Dept Mat Sci & Engn, 1088 Xueyuan Rd, Shenzhen 518055, Guangdong, Peoples R China
2.South Univ Sci & Technol China, Shenzhen Key Lab Printed Organ Elect, 1088 Xueyuan Rd, Shenzhen 518055, Guangdong, Peoples R China
3.Korea Univ, Dept Chem, Seoul 136713, South Korea
4.Nanjing Tech Univ, Jiangsu Natl Synerget Innovat Ctr Adv Mat SICAM, Inst Adv Mat, Key Lab Flexible Elect, 30 South Puzhu Rd, Nanjing 211816, Jiangsu, Peoples R China

Yang, Jie,Uddin, Mohammad Afsar,Tang, Yumin,et al. Quinoxaline-Based Wide Band Gap Polymers for Efficient Nonfullerene Organic Solar Cells with Large Open-Circuit Voltages[J]. ACS Applied Materials & Interfaces,2018,10(27):23235-23246.

Yang, Jie.,Uddin, Mohammad Afsar.,Tang, Yumin.,Wang, Yulun.,Wang, Yang.,...&Guo, Xugang.(2018).Quinoxaline-Based Wide Band Gap Polymers for Efficient Nonfullerene Organic Solar Cells with Large Open-Circuit Voltages.ACS Applied Materials & Interfaces,10(27),23235-23246.

Yang, Jie,et al."Quinoxaline-Based Wide Band Gap Polymers for Efficient Nonfullerene Organic Solar Cells with Large Open-Circuit Voltages".ACS Applied Materials & Interfaces 10.27(2018):23235-23246.