π-Bridge modification of thiazole-bridged DPP polymers for high performance near-IR OSCs

Abstract

Thiophene-bridged and thiazole-bridged diketopyrrolopyrrole (DPP) polymers for near-infrared (near-IR) photovoltaic applications have been investigated via density functional theory (DFT) and Marcus charge transfer theory. Compared with thiophene-bridged DPP polymers, thiazole-bridged polymers have higher ionization potentials (IPs) but poorer optical absorption and worse charge transport capability. Different beneficial substituents replaced the hydrogen atoms (H) on the thiazole rings for the sake of reversing the disadvantages of thiazole-bridged DPP polymers and making these compounds better near-infrared absorbing materials. In order to gain deep insight into the impact of π-bridge modification on the photoelectronic properties of DPP polymers, their electronic structures, absorption capabilities, intramolecular charge transfer properties and charge transport performances have been analyzed. The calculated results reveal that π-bridge modification is a feasible way to improve the light-absorbing capability, electron excitation properties and charge transport performance of thiazole-bridged DPP polymers. It is expected that π-bridge modification can also work for other polymers containing π-bridge units. We hope that our research efforts will be helpful in the designing of new near-IR absorbing materials and could motivate further improvement of organic solar cells.

Molecular Engineering of Hexaazatriphenylene Derivatives toward More Efficient Electron-Transporting Materials for Inverted Perovskite Solar Cells

“…For inverted PSCs, the ETM plays significant roles in protecting the perovskite layer against the erosion of water and oxygen and blocking the transfer of PbI 2 and MAI (decomposed by MAPbI 3 ) through ETM to the top electrode. , The EA values are also used to estimate the ambient stability of the n-type organic semiconductor materials, , where stable ETMs are expected to possess an EA value larger than 2.80 eV . Obviously, HATNASOC7 is stable enough as typical ETMs, which is consistent with experimental observations .…”

Multifunctional Regioisomeric Passivation Strategy for Fabricating Self-Driving, High Detectivity All-Inorganic Perovskite Photodetectors

“…29 In general, the speed of charge carrier transport tends to increase with a higher degree of delocalization within FMO since the orbital delocalization reduces the intramolecular-recombination energy and enhances the electronic coupling between adjacent molecules, then facilitates the carrier transport in both isomer-modified perovskite films. 30 Furthermore, it is worth noting that the HOMO energy level of 14-FABA (6.39 eV) surpasses that of 13-FABA (5.83 eV), suggesting that 14-FABA potentially exhibits a greater inclination to share electrons with Pb 0 or Pb 2+ than that of 13-FABA. 31 As shown in Figure 1d, the electrostatic potentials (ESPs) 32 of 13-FABA and 14-FABA were calculated to understand the passivation mechanisms of FABA isomers on perovskite surface defects.…”

Assessing Effects of Different π bridges on Properties of Random Benzodithiophene-thienothiophene Donor and Non-fullerene Acceptor Based Active Layer

“…Ground state geometries of donor oligomers significantly influence the optoelectronic properties. ,− Thus, it is important to compare the molecular structures of π-bridged donors, with each other as well as with the parent system. Structures of optimized ground state geometries of P1 to TzP1 are shown in Figure .…”