Zoom link: https://kaust.zoom.us/j/98024501440 

Abstract

Over the past years, significant academic progress has been made in enhancing the performance of perovskite light-emitting diodes and organic light-emitting diodes. However, the market demand for devices with even higher efficiencies and improved stability remains pressing. At the same time, the global energy crisis underscores the need to reduce the energy consumption of light-emitting diodes. In this context, understanding and optimizing the interface of (nano)materials within these devices is essential for further performance advancement. This thesis demonstrates interface engineering approaches that not only increase device efficiency but also simplify device complexity and reduce costs. The proposed methods are straightforward, highly versatile, and applicable to advancing optoelectronics. We report the fabrication of highly efficient quasi 2D-perovskite LEDs. We combine the strategies of additive engineering, using an organic molecule with interface engineering by introducing two specific self-assembled monolayers (SAMs), for the first time, as hole-injecting layers. Our optimized devices show greatly enhanced efficiency and stability. Next, we employ various phosphonic acid SAMs and examine their physicochemical properties. Selected SAMs lead to superior performance in green phosphorescent OLEDs. We experimentally elucidate the superior performance of our best devices, studying the origin of this enhanced hole-injection enabled by specific SAMs. Finally, we develop an alternative to traditional indium tin oxide (ITO), anode materials based on treated-PEDOT:PSS that results in remarkably high electrical conductivity. We demonstrate that the proposed PEDOT:PSS can be a universal anode material, by utilizing it in OLEDs and PeroLEDs that show comparable performance to their ITO counterpart devices. We additionally demonstrate that PEDOT:PSS electrodes can be used to fabricate flexible devices.