AP Seminar - Novel Doping Approaches for New Organic Semiconductor Device Concepts

The current generation of organic electronic devices, such as the established OLED technology, is based on amorphous thin films with low carrier mobility due to their disordered molecular orientation. Introducing long-range order in films can significantly improve their charge transport properties and device performance. However, the growth of organic single crystals by conventional approaches, such as physical vapor transport, is difficult for scale-up beyond lab purposes. Here, we present the growth of highly crystalline organic thin-film crystals using the vacuum deposition technique, the current method of choice for industrial applications, where the thickness of the films can be precisely adjusted using epitaxy. In addition, organic dopants can be engineered into the thin-film crystals during the deposition process, which allows us to tune the properties of the individual layers. We then show a number of novel functional devices based on these order layers and discuss the prospect of extension of this fabrication process to a wider range of organic semiconductor materials. Furthermore, I will share some of our recent efforts with semiconductor hydrogel development for bioelectronics applications.