Donor–acceptor cocrystal based on hexakis(alkoxy)triphenylene and perylenediimide derivatives with an ambipolar transporting property

Abstract

An organic donor-acceptor cocrystal with an ambipolar transporting property was constructed based on N,N'-bis(1-ethylpropyl)-perylene-3,4,9,10-tetracarboxylic diimide (EP-PDI) and 2,3,6,7,10,11-hexakis-(hexyloxy)-triphenylene (H6TP). The cocrystal with an alternating stacking of H6TP and EP-PDI molecules was formed through both drop-casting and spin-coating processes, especially at the optimized ratios of H6TP/EP-PDI (2/1, 1/1). The formation of the cocrystal was driven by the strong π-π interaction and the weaker steric hindrance, resulting from the smaller side groups, between the donor and acceptor molecules. Field effect transistors (FETs) based on the H6TP/EP-PDI cocrystal exhibited relatively balanced hole/electron transport, with a hole mobility of 1.14 × 10(-3) cm(2) V(-1) s(-1) and an electron mobility of 1.40 × 10(-3) cm(2) V(-1) s(-1).

Donor–acceptor single cocrystal of coronene and perylene diimide: molecular self-assembly and charge-transfer photoluminescence

“…[14][15][16][17][18][19] To form D-A cocrystals, the molecular structure must be designed so that the D-A interaction exceeds the p-p stacking between PTCDIs, while still maintains the overall geometry matching for the cofacial intermolecular arrangement for a crystalline phase. Because of this structural design challenge, few D-A cocrystal structures of PTCDI was reported, 5 and the high quality cocrystals are thereby highly desired. The single crystalline data thus obtained will provide the theoretical calculation and modeling with precise geometry and conguration of intermolecular arrangement that are crucial for studying the structure-property relationship.…”

“…According to our previous study, 26 assembly of PTCDI-C6 molecules takes two orientations within one monoclinic crystal cell, as usually observed for other PTCDIs that have tertiary or quaternary carbon atoms directly linked to the imide nitrogen atoms. 5,27 Within the PTCDI-C6 crystal, the stacking molecules twist by an appropriate angle to minimize the steric hindrance of cyclohexyl groups. But with the inserting of coronene molecules, the distance between the two PTCDI-C6 molecules was almost doubled, thus diminishing the steric hindrance of side groups.…”

Charge-transfer biexciton annihilation in a donor–acceptor co-crystal yields high-energy long-lived charge carriers

“…If U ¼ 1.67 eV for each of the two excitons in a uniformly spaced Dc + -Ac À -Dc + -Ac À array, we calculate a biexciton energy of DG CT (2) ¼ 3.00 eV. Following annihilation to produce a single, spatially separated electron-hole pair Dc + -A-D-Ac À , with r 12 ¼ 10.2 A, eqn (4) gives the resultant electron-hole pair energy, DG eh ¼ 2.55 eV. This amounts to a free energy change for CT biexciton annihilation of DG A ¼ À0.45 eV, assuring that the charge separation process is indeed spontaneous.…”

“…Organic donor-acceptor (D-A) co-crystals have been shown to possess many interesting properties, among them: semiconducting behavior with appreciable ambipolar charge transport capabilities, [1][2][3][4][5][6][7][8] tunable emission spectra, 5,[9][10][11][12][13] and ferroelectricity. 5,9,14 These structures are also believed to be good candidates for organic eldeffect transistors, 15,16 organic photovoltaics, [17][18][19] photonic logic, 20,21 and near-IR photothermal imaging.…”

Liquid Crystal Ordering on Conjugated Polymers Film Morphology for High Performance

“…The importance of the film morphology in the electronic performance has drawn attention to the exploration of the structure–performance relationship in detail and the development of bottom‐up approaches to regulate the film morphology . After decades of research, people have become aware that some critical physical parameters, including the lattice constant, crystallinity, and orientational parameters, determine the resulting charge mobility of semiconducting polymers in multiscale cases . During anisotropic charge transport in conjugated polymers, delocalized carriers are transported along and between backbones in ordered regions and hop to adjacent chains in disordered regions at different velocities .…”