Intrinsic stability of perovskite materials and their operational stability in light-emitting diodes

Organic–inorganic hybrid perovskite material-based light-emitting diodes (PLEDs) can replace conventional LEDs for next-generation smart devices. The advantages of perovskite materials are narrow band emission, solution-processed device fabrication, and tunable band gaps. However, the stability of PLEDs is a major concern. Perovskite material-based LEDs suffer from ion migration due to the generated electric field during the device operation. Ion migration leads to the degradation of perovskite materials, charge transport layers and metal electrodes, resulting in the breakdown of PLEDs. Other factors for device instability include Joule heating, electrochemical interfacial reaction, atmospheric moisture, and others. Various strategies have been explored to mitigate these challenges, such as optimizing the stoichiometry of perovskite materials, introducing all inorganic element-based perovskite materials, encapsulating the emission layer, use of voltage pulse, device engineering, and defect-free low-bias operative PLEDs. The present review discusses the current status of perovskite-based LEDs in terms of operational stability, degradation mechanisms of perovskites, and strategies to overcome these challenges for a better operational lifetime.