534591-72-5Relevant articles and documents
Highly Efficient Luminescent Solar Concentrators Based on Benzoheterodiazole Dyes with Large Stokes Shifts
Gao, Sheng,Balan, Bamisha,Yoosaf, Karuvath,Monti, Filippo,Bandini, Elisa,Barbieri, Andrea,Armaroli, Nicola
, p. 11013 - 11023 (2020/06/08)
Five extended π-conjugated systems with electron donor (D) and acceptor (A) moieties have been synthesized. Their basic D-A-D structural motif is a benzothiadiazole unit symmetrically equipped with two thiophene rings (S2T). Its variants include 1) the same molecular framework in which sulfur is replaced by selenium (Se2T), also with four thiophene units (Se4T) and 2) a D’-D-A-D system having a N-carbazole donor moiety at one end (CS2T) and a D’-D-A-D-A’ array with a further acceptor carbonyl unit at the other extremity (CS2TCHO). The goal is taking advantage of the intense luminescence and large Stokes shifts of the five molecules for use in luminescent solar concentrators (LSCs). All of them exhibit intense absorption spectra in the UV/Vis region down to 630 nm, which are fully rationalized by DFT. Emission properties have been studied in CH2Cl2 (298 and 77 K) as well as in PMMA and PDMS matrices, measuring photoluminescence quantum yields (up to 98 percent) and other key optical parameters. The dye–PMMA systems show performances comparable to the present state-of-the-art, in terms of optical and external quantum efficiencies (OQE=47.6 percent and EQE=31.3 percent, respectively) and flux gain (F=10.3), with geometric gain close to 90. LSC devices have been fabricated and tested in which the five emitters are embedded in PDMS and their wave-guided VIS luminescence feeds crystalline silicon solar cells.
Synthesis and characterization of cyclopentadithiophene-based low bandgap copolymers containing electron-deficient benzoselenadiazole derivatives for photovoltaic devices
Jung, I.N.Hwan,Hqyeon, Kim,Park, Moo-Jin,Kim, Bongjun,Park, Jong-Hwa,Jeong, Eunjae,Woo, Han Young,Yoo, Seunghyup,Shim, Hong-K.U.
experimental part, p. 1423 - 1432 (2011/03/19)
We have synthesized two cyclopentadithiophene (CDT)-based low bandgap copolymers, poly[(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b′] dithiophene-2,6-diyl)-alt-(benzo[c] [1,2,5]selenadiazole-4,7-diyl)] (PCBSe) and poly[(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-0:3,4-b′]dithiophene-2, 6-diyl)-alt-(4,7dithiophen-2-yl-benzo[c][1,2,5]selenadiazole-5,5'-diyl)] (PCT2BSe), for use in photovoltaic applications. Through the internal charge transfer interaction between the electron-donating CDT unit and the electron-accepting benzoselenadiazole, we realized exceedingly low bandgap polymers with bandgaps of 1.37-1.46 eV, The UV-vis absorption maxima of PCT2BSe were subjected to larger hypsochromic shifts than those of PCBSe, because of the distorted electron donor-acceptor (D-A) structures of the PCT2BSe backbone, These results were supported by the calculations of the D-A complex using the ab initio Hartree-Fock method with a splitvalence 6-31 G* basis set. However, PCT2BSe exhibited a better molar absorption coefficient in the visible region, which can lead to more efficient absorption of sunlight. As a result, PCT2BSe blended with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) exhibited a better photovoltaic performance than PCBSe because of the larger spectral overlap integral with respect to the solar spectrum. Furthermore, when the polymers were blended with PC71BM, PCT2BSe showed the best performance, with an open circuit voltage of 0.55 V, a short-circuit current of 6.63 mA/cm2, and a power conversion efficiency of 1.34% under air mass 1.5 global illumination conditions.
