Nano‐Ground Glass as a Superhydrophilic Template for Printing High‐Performance Organic Single‐Crystal Thin Films

Thin-film devices are typically fabricated through a bottom-up approach, wherein the constituents are deposited sequentially from the bottom to top layer. This method requires the precise management of the heterointerfaces, which leads to complicated integration issues particularly in solution-processed organic thin-film transistors (OTFTs). This limitation arises because a surface suitable for the printing of semiconductors is not necessarily suitable for maximizing the electronic properties of OTFTs. To overcome this, a transfer technique of organic semiconductor (OSC) thin films has been studied. This enables facile transfer of the OSC thin film from a hydrophilic template to any given substrate; thus, the printing substrate and destination substrate can be optimized individually. Here, a nano-ground glass (NGG) is developed whose surface is chemically etched using a mild base. The NGG functions as a thermally stable, superhydrophilic template for printing high-quality single-crystal OSC thin films. To evaluate the practical applicability of the NGG, an n-type OSC, which requires a relatively high temperature of around 150 degrees C during crystal growth, is fabricated. The fabricated OTFTs exhibit an outstanding electron mobility of 2.2 cm(2) V-1 s(-1). The NGG proposed in this study can be utilized for the fabrication of a wide variety of printable materials.