Rational Design of Perylenediimide‐Substituted Triphenylethylene to Electron Transporting Aggregation‐Induced Emission Luminogens (AIEgens) with High Mobility and Near‐Infrared Emission

Abstract

Organic materials with both high electron mobility and strong solid‐state emission are rare although for their importance to advanced organic optoelectronics. In this paper, triphenylethylenes with varying number of perylenediimide (PDI) unit (TriPE‐nPDIs, n = 1−3) are synthesized and their optical and charge‐transporting properties are systematically investigated. All the molecules exhibit strong solid‐stated near infrared (NIR) emission and some of them exhibit aggregation‐enhanced emission characteristics. Organic field‐effect transistors (OFETs) using TriPE‐nPDIs are fabricated. TriPE‐3PDI shows the best performance with maximum quantum yield of ≈30% and optimized electron mobility of over 0.01 cm2 V−1 s−1, which are the highest values among aggregation‐induced emission luminogens with NIR emissions reported so far. Photophysical property investigation and theoretical calculation indicate that the molecular conformation plays an important role on the optical properties of TriPE‐nPDI, while the result from film microstructure study reveals that the film crystallinity influences greatly their OFET device performance.

Organic Semiconductor Single Crystals for Electronics and Photonics

“…The development of high‐performance emissive organic semiconductors is crucial for high OLETs and electrically pumped organic lasers. Although the concept of AIE coined by Tang et al provides an efficient strategy for achieving highly emissive organic molecules (AIEgens) in the solid state, most AIEgens show rather low mobility or have no mobility data, significantly limiting their applications in organic devices . Thus, the rational combination of high mobility and high optical properties by molecular design and crystal engineering remains a challenge.…”

Facile Synthetic Route for Direct Access of Perylenediimide Single Crystals in High Yield through In Situ Crystallization

“…It is noted that planar π‐conjugated fluorophores are prone to exhibit aggregation caused quenching (ACQ) due to strong aromatic cycle stacking. Strategies like introducing bulky substituents at bay position of PDIs to break planarity and prevent strong aromatic stacking has been employed to generate solid state emissive materials . PDI‐2 and PDI‐3 prepared at different temperature also showed similar absorption and fluorescence modulation (Figure S11 and Figure S12).…”

Bis‐Naphthalene Cleft with Aggregation‐Induced Emission Properties through Lone‐Pair⋅⋅⋅π Interactions

“…The emission lifetimes of 1 are 2.6 ns in DMF and 6.9 ns in the solution with f w =90 % (Figure S8). The prolonged lifetime matches with its AIE properties …”

“…The prolonged lifetime matches with its AIE properties. [17] The significantly increased fluorescencei ntensity and quantum yield with the addition of poor solvent to its solution in a good solvent suggest that compound 1 is an AIEgen. However, furthere videncew ould be needed to support the idea that the emissioni scaused by aggregation.U V/Vis spectra of 1 in DMF and DMF/H 2 O( 3:7) mixture werea lmosti dentical in the visible region (Figure 2a).…”