Fabrication and Characterization of Organic Single Crystal‐Based Light‐Emitting Devices with Improved Contact Between the Metallic Electrodes and Crystal

Organic single crystals have attracted great attention because of their advantages of high charge‐carrier mobility, high chemical purity, and potential for flexible optoelectronic devices. However, their intrinsic properties of sensitive to organic solvent and fragile result in a difficulty in the fabrication of the organic crystal‐based devices. In this work, a simple and non‐destructive technique of template stripping is employed to fabricate single‐crystal‐based organic light‐emitting devices (OLEDs). Efficient and uniform carrier injection induced by an improved contact between crystals and both top and bottom electrodes is realized, so that a homogeneous and bright electroluminescence (EL) are obtained. Highly polarized EL and even white emission is also observed. Moreover, the crystal‐based OLEDs exhibit good flexibility, and keep stable EL under a small bending radius and after repeated bending. It is expectable that this technique would support broad applications of the organic single crystals in the crystal‐based optoelectronic devices.