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.