249575-14-2Relevant academic research and scientific papers
Effect of incorporated nitrogens on the planarity and photovoltaic performance of donor-acceptor copolymers
Cho, Han-Hee,Kang, Tae Eui,Kim, Ki-Hyun,Kang, Hyunbum,Kim, Hyeong Jun,Kim, Bumjoon J.
, p. 6415 - 6423 (2012)
Systematic control of the chemical structure of conjugated polymers is critically important to elucidate the relationship between the conjugated polymer structures and properties and to optimize their performance in bulk heterojunction (BHJ) polymer solar cell (PSC) devices. Herein, we synthesized three new copolymers, i.e., P0, P1, and P2; these copolymers contain the same benzodithiophene donor unit but have different acceptor units with different numbers of nitrogen atoms in the range of 0-2. The effects of the introduced nitrogen atoms on the structural, optical, electrical, and photovoltaic properties of the conjugated polymers were investigated; the structural properties of the polymers, in particular, were studied using both experimental (grazing-incidence X-ray scattering (GIXS) measurements) and computational methods (molecular simulation). As the number of introduced nitrogen atoms increased, the planarity of the main chain conformation increased in the order of P0 a red-shifting at the onset of absorption in the polymer film from 544 to 585 nm, a downshift in the lowest unoccupied molecular orbital (LUMO) energy level from -3.02 to -3.26 eV, and an increase in the hole mobility from 2.33 × 10-6 to 3.78 × 10-5 cm2/(V s). As a result, we observed dramatically enhanced performance of the PSCs in the order of P0 61BM device exhibited a 3.5-fold improvement in power conversion efficiency (PCE) compared to that of P0:PC61BM. The further optimization of P2 with PC 71BM showed the PCE of 3.22%.
Studies on the preference of multiple coupling in the introduction of thiophene ring into poly-halogenated aromatic compounds with nickel NHC catalyst
Tanaka, Shota,Tatsuta, Go,Sugie, Atsushi,Mori, Atsunori
, p. 1976 - 1979 (2013/04/23)
Several thiophene derivatives can be deprotonated by the combination of ethyl magnesium chloride (EtMgCl) and a catalytic amount of 2,2,6,6- tetramethylpiperidine (TMP-H). The metalated 3-hexylthiophene reacts with 2,3- and 2,5-dibromothiophenes in the presence of a nickel catalyst bearing NHC ligand (IPr) to afford the di-coupled product exclusively along with recovery of dibromothiophene albeit the equimolar reaction. The 1:1 reaction of 3-hexylthiophene with dibrominated benzene derivatives also gives di-coupled product as a sole product.
