Laser‐Printed Organic Thin‐Film Transistors

Abstract

Solution deposition of organic opto-electronic materials enables fast roll-to-roll manufacturing of photonic and electronic devices on any type of substrate and at low cost. But controlling the film microstructure when it crystallizes from solution can be challenging. This represents a major limitation of this technology, since the microstructure, in turn, governs the charge transport properties of the material. Further, the solvents typically used are hazardous, which precludes their incorporation in large-scale manufacturing processes. Here, we report the first ever organic thin-film transistor fabricated with an electrophotographic laser printing process using a standard office laser printer. This completely solvent-free additive manufacturing method allows for simultaneous deposition, purification, and patterning of the organic semiconductor layer. Laser printed transistors using triisopropylsilylethynyl pentacene as the semiconductor layer were realized on flexible substrates and characterized, making this a successful first demonstration of the potential of laser printing of organic semiconductors.

Contact Resistance in Organic Field‐Effect Transistors: Conquering the Barrier

“…One of the key advantages of organic semiconductors is their compatibility with printing techniques . To fully take advantage of this feature toward the development of low‐cost (opto‐)electronic devices, the materials and processing necessary for the other device layers must offer the same opportunities.…”

Direct Laser Writing: From Materials Synthesis and Conversion to Electronic Device Processing

“…[ 347 ] In the last 15 years, reports of DLW employed in TFT fabrication have focused on fabricating constituent layers of those devices (mostly applied on contact electrode patterning) or improving their characteristics. [ 22,31,348–350,32,37,88,102,133,239,240,254 ] However, most of these works are from the last six years, showing a higher demand for low‐cost production techniques and easier scale‐up to large area manufacturing enabled by DLW paradigms.…”

“…reported the first organic TFT in which the organic semiconductor layer was written using DLW, by photochemical conversion and annealing of a sol‐gel indium nitrate precursor using a KrF excimer laser, to implement an In 2 O 3 n‐type channel made from this oxide semiconductor. [ 349 ] The laser‐annealed In 2 O 3 TFTs showed higher mobility (13 cm 2 V −1 s −1 ) when compared with the reference device annealed at a higher temperature (250 °C). In 2020, E. Carlos et al.…”

Organic Semiconductors Derived from Dinaphtho-Fused s-Indacenes: How Molecular Structure and Film Morphology Influence Thin-Film Transistor Performance

“…Organic semiconductors have maintained broad academic and industrial attention due to their distinctive optoelectronic properties and the applications they can enable. Such devices are obtained by unconventional manufacturing such as spray coating, 1 inkjet printing, 2,3 or laser printing 4 ̵ low-cost processes occurring in mild conditions, which may enable new device functionalities that are either impossible or not cost-effective with current technologies (lightweight, mechanical flexibility, conformability, and transparency, etc.). The ability to control the properties through chemical design provides a versatile tool for the development of materials with specific function in mind, but unfortunately this task is challenged by the intricate relationships among the molecular structure, processing, film morphologies (molecular to mesoscale), and ultimate materials performance in device applications.…”