Effects of electron-withdrawing group and π-conjugation length in donor-acceptor oligothiophenes on their properties and performance in non-fullerene organic solar cells

Thiophene- and bithiophene-based π-conjugated Schiff base oligomers containing binaphthalene moieties in the backbone. Properties and computational simulations

“…These results showed that o-AZdAN1Th had slightly higher thermal resistance than o-AZdAN2Th, which could be attributed to its higher molecular weight and closer conformation that promotes higher oligomeric stacking forces. 17,23 DTGA curves showed that the maximum degradation rate is 27 °C higher for o-AZdAN1Th. Although AZdAN2Th has a longer π-conjugated repeating unit, the higher molecular weight promotes higher stacking strength between the chains in o-AZdAN1Th, which ratifies what was observed in the TGA curves.…”

“…These properties can be easily tuned by modifying the structure of the thiophene units along the backbone. 16,17 In photovoltaic devices, such as bulk heterojunction solar cells, these modulations lead to monomers with different structural configurations for new n-and p-type copolymers p-conjugated for the absorber layer in this multilayer structure device architecture. 18 To date, improvements in solar energy conversion efficiency have been reported for polythiophene derivatives in relation to chemical design as well as device configuration, where the efficiency has scaled values above 15-20%.…”

“…18 To date, improvements in solar energy conversion efficiency have been reported for polythiophene derivatives in relation to chemical design as well as device configuration, where the efficiency has scaled values above 15-20%. 17,[19][20][21][22] Poly(azomethine)s (PAZs), also called poly(imine)s or Schiff base polymers, are a type of π-conjugated polymeric materials. These polymers have imine bonds (R-CHvN-R′) along their chains, 23,24 which are isoelectronic with vinyl bonds (CHvCH-), allowing to obtain materials with optical and electronic properties similar to poly(vinylene) derivatives.…”

Spectrally Selective Full-Color Single-Component Organic Photodetectors Based on Donor-Acceptor Conjugated Molecules

“…The donor-acceptor concept in the molecular design of the π-conjugated system opens wide possibilities for tuning their key properties, such as absorption spectra, charge-carrier mobilities, charge photogeneration efficiency, and stability [ 26 , 27 ]. Changing the donor or/and acceptor group, as well as the type and the length of the conjugated π-spacer between them, allows for adjusting the frontier orbitals energies, absorption and luminescence spectra, phase behavior, photophysics, and charge separation [ 23 , 24 , 28 ]. Various donor-acceptor conjugated molecules of a linear and star-shaped structure were synthesized, and their physicochemical and photovoltaic properties were investigated [ 23 , 24 , 28 , 29 , 30 ].…”

“…Changing the donor or/and acceptor group, as well as the type and the length of the conjugated π-spacer between them, allows for adjusting the frontier orbitals energies, absorption and luminescence spectra, phase behavior, photophysics, and charge separation [ 23 , 24 , 28 ]. Various donor-acceptor conjugated molecules of a linear and star-shaped structure were synthesized, and their physicochemical and photovoltaic properties were investigated [ 23 , 24 , 28 , 29 , 30 ]. If the molecular absorption spectra are close to the photosensitive response of eye photoreceptors (blue cones, rods, green cones, red cones), they can be used to create full-color retinal prostheses [ 6 ].…”