The ratio and topology effects of benzodithiophene donor–benzooxadiazole acceptor fragments on the optoelectronic properties of donor molecules toward solar cell materials

Abstract

A series of conjugated donor molecules (DmAnSq where m = 1-4, n = 1-7 while D = benzodithiophene, A = benzooxadiazole and S denotes ethyne spacers between D and A or D and D fragments) with various ratios of D/A fragments and topologies have been designed and investigated for OPV applications. An increase in the ratio of the acceptor fragment with respect to the donor fragment decreases the LUMO energy level and narrows the Eg for the designed molecule. More vertically (C4 and C8 substituted phenyl ring positions) bonded acceptor fragments than linearly (C2 and C6 substituted thiophene ring positions) bonded fragments result in a significant red shift in the maximum absorption wavelength. While, linearly bonded fragments lead to stronger absorption bands. Molecules with D-A-D topology exhibit more significant optical and electronic characteristics than those with D-D topology. All donor molecules (m = 2-4) of the D-A-D type show lower λh values than those of 1 donor containing (DAn) molecules. D-D type molecules show only lower λe values than DAn molecules because of the presence of a second donor fragment. The charge transfer phenomenon is shape dependent. The branched or anisotropic X, H, π, n, and square shaped molecules display higher charge transfer rates than the corresponding linear isomers due to better dimensionality. On the basis of these results, we suggest that designed donor and corresponding matched acceptor molecules have potential to act as promising candidates in solar cell devices.

Shedding light on the optical and nonlinear optical properties of superalkali-doped borophene

“…Moreover, the density of states (DOS), natural bond orbital (NBO) charges, HOMO-LUMO band gap was estimated at the same computational levels. The density of states (DOS) analysis was performed with the help of PyMOlyze software [41]. The charge transfer phenomenon between borophene (B 36 ) and Li 3 O was calculated by natural bond (NBO) analysis [42].…”

Substitutional effect of different bridging groups on optical and charge transfer properties of small bipolar molecules for OLEDs

“…Nowadays, renewable energy sources and low‐cost electronic devices are key topics in the fields of both industrial and academic research. The sustainable development of new electronic technology with utilization of less electricity is a global challenge . In this regard, a latest valuable example of technology is organic light emitting diodes (OLEDs).…”

“…The sustainable development of new electronic technology with utilization of less electricity is a global challenge. [1][2][3][4][5][6] In this regard, a latest valuable example of technology is organic light emitting diodes (OLEDs). OLEDs have been recognized as the shining stars in discipline of technology revolution like in lighting and digital display technologies.…”