New π‐Conjugated polymers containing 4H,4′H‐[1,1′‐Bithieno [3,4‐C]Pyrrole]‐4,4′,6,6′(5H,5′H)‐Tetraone (biTPD) units and their application to thin‐Film transistors and photovoltaic cells

Lee, Dong Hoon; Kim, Kyung Hwan; Shin, Jicheol; Cho, Min Ju; Choi, Dong Hoon

doi:10.1002/pola.27963

“…We used 2-octyldodecyl side chains on 2TPD to increase the solubility of the resulting polymer and also provide satisfactory steric hindrance to prevent aggregation. [41,45] Likewise, even though IDT-based copolymers in general show low degree of long-range ordering in the solid state compared to semicrystalline polymers, [46][47][48] we functionalized the planar IDT backbone with bulky p-hexylphenyl substituents (Figure 1b,c), which are expected to further reduce polymer chain aggregations as they align somewhat perpendicular to the planar IDT backbone. [49,50] We obtained higher number-average molecular weight (M n ) for PIDT-2TPD (55.7 kg mol −1 , polydispersity index (PDI) 2.4) due to the much longer side chains attached on 2TPD as compared to PIDT-TPD (26.3 kg mol −1 , PDI 2.1), yet comparable PDIs.…”

Section: Doi: 101002/adma201706584mentioning

confidence: 99%

Efficient Near‐Infrared Electroluminescence at 840 nm with “Metal‐Free” Small‐Molecule:Polymer Blends

Minotto

¹

,

Murto

²

,

Genene

³

et al. 2018

View full text Add to dashboard Cite

The development of efficient and biocompatible organic near-infrared emitters is attractive for many applications, spanning from photodynamic therapy [1] to light fidelity (Li-Fi) all-optical networking systems. [2][3][4] In particular, the range 700-1000 nm is interesting for medical applications, given the semitransparency of biological tissue in this spectral interval, [5] and we will specifically refer to this range as near-infrared (NIR) in the following text. Compared to conventional inorganic materials, organic NIR emitters are interesting also for their mechanical conformability, which makes them appealing for the integration in flexible and stretchable devices. [6] Furthermore, the metal-free organic light-emitting materials can be a cheap and biocompatible alternative to inorganic ones for application in wearable, implantable, or in vivo medical applications, such as for sensing of body temperature, heart and respiration rates, blood pressure, glucose level, and oxygenation. [7] In the search for ever-higher efficiencies, several classes of materials have been investigated, such as perovskite-structured methylammonium lead halides, [8][9][10] quantum dots, [11] and organometallic phosphorescent complexes. [12][13][14][15][16][17][18][19] However, although such hybrid materials afford substantial electroluminescence (EL) external quantum efficiency (EQE) in the NIR, in some cases exceeding 10% [8,10] or even 20% or so, [13] their use of heavy, toxic, and/or costly metals is not ideal for manufacturing, sustainability, environmental impact, and, in perspective, biocompatibility. Furthermore, in such hybrid systems, and in general in materials that leverage triplet excitons to boost the EQE, [20,21] exciton recombination dynamics typically fall in the hundreds of nanoseconds or even in the microsecond (or longer) range, which intrinsically limits the bandwidth when integrated in devices for telecommunications. For Li-Fi applications, [2][3][4] fluorescent molecular and polymeric materials are preferred, given that the typical fluorescence lifetime of these materials is of the order of few nanoseconds or less, thereby ideally allowing data transmission rates up to the Gb s −1 regime.In the last decade, scientists have attempted different strategies to develop heavy-metal-free NIR fluorescent organic light-emitting diodes (OLEDs), with chemical design essentially revolving around the careful combination of donor and acceptor groups to both tune the spectral range (up to 1000 nm) and maximize the EQE. [22][23][24][25][26][27][28][29][30][31][32][33] Very recently, we have, for Due to the so-called energy-gap law and aggregation quenching, the efficiency of organic light-emitting diodes (OLEDs) emitting above 800 nm is significantly lower than that of visible ones. Successful exploitation of triplet emission in phosphorescent materials containing heavy metals has been reported, with OLEDs achieving remarkable external quantum efficiencies (EQEs) up to 3.8% (peak wavelength > 800 nm). For OLEDs incorporating f...

show abstract

An n‐Type Polythiophene Derivative with Excellent Thermoelectric Performance

Deng

¹

,

Dong

²

,

Liu

³

et al. 2023

Angewandte Chemie

2

0

View full text Add to dashboard Cite

Typical n‐type conjugated polymers are based on fused‐ring electron‐accepting building blocks. Herein, we report a non‐fused‐ring strategy to design n‐type conjugated polymers, i.e. introducing electron‐withdrawing imide or cyano groups to each thiophene unit of a non‐fused‐ring polythiophene backbone. The resulting polymer, n‐PT1, shows low LUMO/HOMO energy levels of −3.91 eV/−6.22 eV, high electron mobility of 0.39 cm2 V−1 s−1 and high crystallinity in thin film. After n‐doping, n‐PT1 exhibits excellent thermoelectric performance with an electrical conductivity of 61.2 S cm−1 and a power factor (PF) of 141.7 μW m−1 K−2. This PF is the highest value reported so far for n‐type conjugated polymers and this is the first time for polythiophene derivatives to be used in n‐type organic thermoelectrics. The excellent thermoelectric performance of n‐PT1 is due to its superior tolerance to doping. This work indicates that polythiophene derivatives without fused rings are low‐cost and high‐performance n‐type conjugated polymers.

show abstract

An n‐Type Polythiophene Derivative with Excellent Thermoelectric Performance

Deng

¹

,

Dong

²

,

Liu

³

et al. 2023

View full text Add to dashboard Cite

Typical n‐type conjugated polymers are based on fused‐ring electron‐accepting building blocks. Herein, we report a non‐fused‐ring strategy to design n‐type conjugated polymers, i.e. introducing electron‐withdrawing imide or cyano groups to each thiophene unit of a non‐fused‐ring polythiophene backbone. The resulting polymer, n‐PT1, shows low LUMO/HOMO energy levels of −3.91 eV/−6.22 eV, high electron mobility of 0.39 cm2 V−1 s−1 and high crystallinity in thin film. After n‐doping, n‐PT1 exhibits excellent thermoelectric performance with an electrical conductivity of 61.2 S cm−1 and a power factor (PF) of 141.7 μW m−1 K−2. This PF is the highest value reported so far for n‐type conjugated polymers and this is the first time for polythiophene derivatives to be used in n‐type organic thermoelectrics. The excellent thermoelectric performance of n‐PT1 is due to its superior tolerance to doping. This work indicates that polythiophene derivatives without fused rings are low‐cost and high‐performance n‐type conjugated polymers.

show abstract

New π‐Conjugated polymers containing 4H,4′H‐[1,1′‐Bithieno [3,4‐C]Pyrrole]‐4,4′,6,6′(5H,5′H)‐Tetraone (biTPD) units and their application to thin‐Film transistors and photovoltaic cells

Cited by 7 publications

References 23 publications

Efficient Near‐Infrared Electroluminescence at 840 nm with “Metal‐Free” Small‐Molecule:Polymer Blends

Efficient Near‐Infrared Electroluminescence at 840 nm with “Metal‐Free” Small‐Molecule:Polymer Blends

An n‐Type Polythiophene Derivative with Excellent Thermoelectric Performance

An n‐Type Polythiophene Derivative with Excellent Thermoelectric Performance

Contact Info

Product

Resources

About