Electron Transport in Naphthalene Diimide Derivatives

Abstract

Two naphthalene diimides derivatives containing two different (alkyl and alkoxyphenyl) N-substituents were studied, namely, N,N′-bis(sec-butyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide (NDI-s-Bu) and N,N′-bis(4-n-hexyloxyphenyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide (NDI-4-n-OHePh). These compounds are known to exhibit electron transport due to their electron-deficient character evidenced by high electron affinity (EA) values, determined by electrochemical methods and a low-lying lowest unoccupied molecular orbital (LUMO) level, predicted by density functional theory (DFT) calculations. These parameters make the studied organic semiconductors stable in operating conditions and resistant to electron trapping, facilitating, in this manner, electron transport in thin solid layers. Current–voltage characteristics, obtained for the manufactured electron-only devices operating in the low voltage range, yielded mobilities of 4.3 × 10−4 cm2V−1s−1 and 4.6 × 10−6 cm2V−1s−1 for (NDI-s-Bu) and (NDI-4-n-OHePh), respectively. Their electron transport characteristics were described using the drift–diffusion model. The studied organic semiconductors can be considered as excellent candidates for the electron transporting layers in organic photovoltaic cells and light-emitting diodes

Synthesis, Solution, and Solid State Properties of Homological Dialkylated Naphthalene Diimides—A Systematic Review of Molecules for Next-Generation Organic Electronics

“…The solubility of NDIs in cyclohexane, n-hexane, or n-heptane is significantly lower. In our study, we tested and verified the solubility of NDIs in solvents commonly used in the fabrication of organic electronic films [ 5 , 51 , 53 ]. The solubility of NDIs was, therefore, tested in chloroform, 1,2-dichlorobenzene, and toluene—good solvents for NDIs, as well as n-heptane—a poor solvent [ 49 , 53 , 54 ].…”

“…The solubility of the NDIC3, NDIC4, NDIC9, and NDIC11 in chloroform was 46.9 ± 1.5, 65.5 ± 1.6, 47 ± 1.0, and 15.15 ± 0.6 mg/mL, respectively. Considering applications of NDIs in, for instance, printed organic electronics, that solubility in the case of all NDIs exceeds usual needs since typically used concentrations oscillate within 2–20 mg/mL [ 5 , 51 , 53 ]. Conversely, the solubility of NDIs in n-heptane ( Figure 3 and Table S4 ) was two orders of magnitude lower than in chloroform.…”

“…They exhibit high chemical, thermal, and oxidative stability. The high stability in conjunction with their redox activity [ 1 ], spectroscopic [ 2 , 3 ], and electronic properties [ 4 , 5 ] make NDIs interesting for materials scientists and supramolecular chemists. NDIs reveal higher field-effect electron mobility than pyromellitic diimides (PyDI, Figure 1 ) [ 6 , 7 ].…”

High-Mobility Naphthalene Diimide Derivatives Revealed by Raman-Based In Silico Screening

“…Note that the six crystals considered in this work ( Figure 1 ) were characterized by Z red = 1, unlike the crystals of NDI and naphthodithiophene diimide derivatives with Z red = 2, for which electron mobility has recently been studied, both experimentally and theoretically [ 66 , 67 ].…”

Synthesis, optical properties and cation mediated tuning of the reduction potentials of core-annulated naphthalene diimide derivatives

“…The molecular geometry of a ImPyDI in its ground state was optimised using DFT/B3LYP with the 6-31+G(d,p) basis set in chloroform. 20 The frontier orbitals of the doubly-annulated dye calculated by the DFT method revealed the absence of the lowest unoccupied molecular orbital (LUMO) level over the nitrogen atoms (Fig. 2a).…”