Field‐Effect Transistors Based on 2D Organic Semiconductors Developed by a Hybrid Deposition Method

Abstract

Solution‐processed 2D organic semiconductors (OSCs) have drawn considerable attention because of their novel applications from flexible optoelectronics to biosensors. However, obtaining well‐oriented sheets of 2D organic materials with low defect density still poses a challenge. Here, a highly crystallized 2,9‐didecyldinaphtho[2,3‐b:2′,3′‐f]thieno[3,2‐b]thiophene (C10‐DNTT) monolayer crystal with large‐area uniformity is obtained by an ultraslow shearing (USS) method and its growth pattern shows a kinetic Wulff's construction supported by theoretical calculations of surface energies. The resulting seamless and highly crystalline monolayers are then used as templates for thermally depositing another C10‐DNTT ultrathin top‐up film. The organic thin films deposited by this hybrid approach show an interesting coherence structure with a copied molecular orientation of the templating crystal. The organic field‐effect transistors developed by these hybrid C10‐DNTT films exhibit improved carrier mobility of 14.7 cm2 V−1 s−1 as compared with 7.3 cm2 V−1 s−1 achieved by pure thermal evaporation (100% improvement) and 2.8 cm2 V−1 s−1 achieved by solution sheared monolayer C10‐DNTT. This work establishes a simple yet effective approach for fabricating high‐performance and low‐cost electronics on a large scale.

Newly Synthesized Nonvacuum Processed High‐k Polymeric Dielectrics with Carboxyl Functionality for Highly Stable Operating Printed Transistor Applications

“…[10b] Therefore, the crystalline structures of the OSC films were analyzed with the polymeric dielectrics. Figure 1e, respectively) than the lowest surface energy for the C 10 -DNTT crystal planes (49.83 mJ m −2 ), [25] which fabricate a similar crystalline structure of OSC at thin film formation (≈50 nm).…”

Crystallized Monolayer Semiconductor for Ohmic Contact Resistance, High Intrinsic Gain, and High Current Density

“…Third, the considerably lower interlayer adhesion compared with intralayer π-π overlapping allows the formation of crystals with high aspect ratio, e.g., 1L-and 2L-crystals, while under low-speed shearing and well controlled solvent evaporation as presented in our previous work. [20][21][22] With precise control of the temperature (from 60 to 65 °C) and the shearing speed (from 2 to 3 µm s −1 ), the 1L-and 2L-crystals with singlecrystalline domains extending over several millimeters can be achieved. The structural information of the 1L-crystals was measured by X-ray reflectivity (XRR) and is shown in Figure 1a.…”

Approaches to modelling the shape of nanocrystals

“…Indeed, a significant number of recent papers incorrectly described kinetically controlled nanocrystal shapes as thermodynamic ones [ 65 – 67 ] with others explicitly stating that Wulff constructions can only be used to determine thermodynamic equilibrium [ 68 , 69 ]. The propagation of the incorrect idea of “one Wulff construction” has not exclusively led to confusion regarding kinetics vs thermodynamics: the Winterbottom construction has been referred to as “the Wulff construction” [ 70 ] or “modified Wulff construction” [ 71 ], and the kinetic Wulff construction has been called a “modified Wulff construction” [ 72 ]. These names are often not strictly incorrect, but the use of a more precise terminology would clarify which mathematical construct is used and help readers apply them in their own systems.…”