Enhancing Perovskite LEDs for Visible Light Communication through Molecular Interface Engineering

Description

Perovskite light-emitting diodes (PeLEDs) have recently attracted considerable attention due to their potential utility in energy-efficient lighting, high-resolution displays, and, notably, visible light communications (VLC). The intrinsically high mobility and rapid response times of perovskite semiconductors make them well-suited for VLC applications that require high data rates. However, the broader adoption of this promising technology is currently impeded by several challenges, including non-radiative losses, significant contact resistance, and stability issues induced by ion migration during high current operation. This research proposal aims to confront these challenges by employing a novel method: molecular interface engineering of PeLEDs. This methodology consists of manipulating the chemistry and energy levels at the interfaces between the perovskite and charge transport layers. By meticulously selecting and designing the molecular structures of the interfacial layers, we aim to optimize electronic coupling, decrease defect density, and regulate ion migration—parameters that are critical for enhancing device performance. The first objective of this proposal is to curtail non-radiative recombination losses at the interfaces. By improving light extraction, we target to deliver PeLED with an external quantum efficiency (EQE) exceeding 30%. Achieving this substantial increase in efficiency is essential for establishing PeLEDs as a practical solution for energy-saving light sources. Our second objective is to augment the stability of PeLEDs under electrical stress, targeting operational lifetimes (T50) beyond 10,000 hours at practical brightness levels. We propose to manage ion migration by modifying the interfaces — an approach that could notably improve device durability. Our third objective is to circumvent the speed constraints of PeLEDs, which are presently limited by electrode resistance and charge trapping. We aim to raise the modulation bandwidth into the MHz range for sub-mm-sized devices—a significant enhancement that will increase the data handling capacity of PeLEDs, a critical factor in VLC applications. In parallel with these objectives, our research will also delve into understanding the recombination dynamics through ultrafast spectroscopy studies. These investigations will yield crucial insights into interfacial defect chemistry and recombination processes, which can be translated into practical design principles and interface models for PeLED development. In summary, this research has the potential to expedite the adoption of PeLEDs in lighting, displays, and, particularly, VLC technologies. By addressing the primary obstacles of PeLEDs, our research could make significant contributions to both the scientific community and commercial sectors, thereby push forward the development and application of advanced PeLEDs.