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

Abstract 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 °C during crystal growth, is fabricated. The fabricated OTFTs exhibit an outstanding electron mobility of 2.2 cm² V⁻¹ s⁻¹. The NGG proposed in this study can be utilized for the fabrication of a wide variety of printable materials.