Nitrogen-Containing Perylene Diimides: Molecular Design, Robust Aggregated Structures, and Advances in n-Type Organic Semiconductors

Abstract

Metrics & MoreArticle Recommendations CONSPECTUS: Organic semiconductors (OSCs) have attracted much attention because of their potential applications for flexible and printed electronic devices and thus have been extensively investigated in a variety of research fields, such as organic chemistry, solid-state physics, and device physics and engineering. Organic thin-film transistors (OTFTs), a class of OSC-based devices, have been expected to be an alternative of silicon-based metal oxide semiconductor field-effect transistors (MOS-FETs), which is the indispensable element for most of the current electronic devices. However, the noncovalently aggregated, van der Waals solid nature of the OSCs, by contrast to covalently bound silicon, conventionally exhibits lower carrier mobilities, limiting the practical applications of OTFTs. In particular, electron-transporting (i.e., n-type) OSCs lag behind their hole-transporting (p-type) counterparts in carrier mobility and ambient stability as OTFTs. This is primarily because of the difficulty in achieving compatibility between the aggregated structure exhibiting excellent carrier mobility and that with enough electron affinity. Recent understandings of carrier transport in OSCs explain that large and two-dimensionally isotropic transfer integrals coupled with small fluctuations are crucial for high carrier mobilities. In addition, from a practical point of view, the compatibility with practical device processes is highly required. Rational molecular design principles, therefore, are still demanded for developing OSCs and OTFTs toward high-end device applications. Herein, we will show our recent progress in the development of n-type OSCs with the key π-electron core (π-core) of benzo[de]isoquinolino[1,8-gh]quinolinetetracarboxylic diimide (BQQDI) on the basis of single-crystal OTFT technologies and the band-transport model enabled by two-dimensional molecular packing arrangements. The critical point is the introduction of electronegative nitrogen atoms into the π-core: the nitrogen atoms in BQQDI not only deepen the molecular orbital energies but also allow hydrogen-bonding-like attractive intermolecular interactions to control the aggregated structures, unlike the conventional role of the nitrogen introduced into OSCs only for the former role. Hence, the BQQDI analogues exhibit air-stable OTFT behavior and two-dimensional brickwork packing structures. Specifically, phenethyl-substituted analogue (PhC 2 −BQQDI) has been shown as the first principal BQQDI-based material, demonstrating solution-processable thin-film single crystals, fewer anisotropic transfer integrals, and an effective suppression of molecular motions, leading to band-like electron-transport properties and stress-durable nchannel OTFT performances, in conjunction with the support of computational calculations. Insights into more fundamental points of view have been found by side-chain derivatization and OTFT studies on polycrystalline and single-crystal films. We hope that this Account provides readers with ...

Donor–Acceptor Hybrid Heterostructures: An Emerging Class of Photoactive Materials with Inorganic and Organic Semiconductive Components

“…To date, the B3LYP hybrid functional, M06‐2X hybrid functional, GGA/PBE functional, and GGA/PW91 functional are frequently used to calculate the HOMO and LUMO energy levels of organic components, isolated inorganic clusters, and discrete D‐A structures. [ 33–67 ] Meanwhile, the local Perdew–Burke–Ernzerhof (PBE), the PBE + U actualization of DFT + U, the local PBEsol, the hybrid functional HSE06, and the local HLE17 are the most commonly used functionals for predicting the band gap of infinite D‐A hybrids. [ 55,68–70 ] Apart from the energy levels of D‐A hybrid heterostructures, supramolecular interactions between donors and acceptors (such as anion–π interactions, hydrogen bonding interactions) are also essential because they can serve as electron transfer pathway and improve PIET.…”

“…[56] Third, the incorporation of functional groups such as amino, hydroxyl, nitro, and halogen could further modulate their HOMO and LUMO energy levels and band gaps. [57] For instance, our group have prepared two bay-substituted PDI bearing two electron-withdrawing nitro groups (PDI 2) as well as two electron-donating 4-tert-butylphenoxyl groups (PDI 3). [58] In comparison with unsubstituted PDI 1, the introduction of electron-donating phenoxy groups decrease both HOMO and LUMO energies (from −5.98 to −5.42 eV for HOMO and from −3.43 to −2.44 eV for LUMO).…”

Multiple-boron–nitrogen (multi-BN) doped π-conjugated systems for optoelectronics

“…The other reason why perylene derivatives have been extensively studied is that they can be extended to a new ubiquitous class of molecules -perylene diimides (PDIs) which have high chemical stability with high electron affinities and are regarded as one of the best n-type classes of semiconductors. [66][67][68][69][70] Wang and coworkers continued using BN-naphthalene as the building block and exploiting a similar strategy which was used in the synthesis of bis-BN-doped perylenes to construct bis-BN-doped PDIs 24 (Fig. 7).…”

bay-Dissymmetrical hetero- and Aza-Benzannulated PeryleneDiimides as new n-type semiconductors

“…However, simple monomeric AzaBPDIs have never been explored as ntype semiconductors, although N-decorated electron-poor organic semiconductors recently proved more and more appealing. [21][22][23][24] In continuation of our work on the design of multi-AzaBPDI assemblies, we present the electronic, optical and semiconducting properties of hetero-annulated AzaBPDIs (named Het-AzaBPDIs). Simple phenyl-appended AzaBPDI 1 has been compared to heteroannulated N-AzaBPDI 2, S-AzaBPDI 3 and Se-AzaBPDI 4 (Fig.…”