In recent years, perovskite materials have been employed in the fabrication of light-emitting diodes (LEDs) because of their adjustable bandgaps, long carrier diffusion lengths, high exciton binding energies, and high fluorescence quantum yields. Hence, they exhibit considerable potential for use in display and lighting applications. In 2014, Tan et al. developed a perovskite light-emitting diode (PeLED) that emits light at room temperature employing a class of metal halide perovskites (MHPs). In subsequent studies, scientists have conducted extensive research on perovskite crystal quality and device structure, resulting in rapid advancements in PeLED technology, particularly with regard to the enhancement of electroluminescence performance.

Although the performance of PeLEDs has approached or even surpassed that of other commercial LEDs, numerous challenges inherent to the production and application of these devices remain unaddressed. PeLEDs exhibit poor stability and the manufacturing process is constrained by the difficulty involved in fabricating large-area devices, environmental pollution caused by lead, and leakage of organic solvents. Device stability is the most significant in these challenges and constitutes a noteworthy impediment to the commercialization of PeLED technology. Additionally, the operational lifetimes of PeLEDs are still shorter than those of mature organic and quantum dot light-emitting diodes by 2?3 orders of magnitude. The poor stability of PeLEDs can be attributed to the variety of defects inherent to perovskite materials. The most notable characteristics are deep-level defects, which can be considered the primary factors influencing device stability. Furthermore, the interfacial charge accumulation, ion migration, and Joule heat generated during the operation of a PeLED device, as well as the sensitivity of the devices to environmental factors (humidity, light, and temperature) caused by defects accelerate interfacial degradation, resulting in device damage. Although PeLED technology continues to evolve, its commercialization will inevitably be hindered by these stability issues.

This review briefly discusses the evaluation criteria for device stability and analyzes their advantages and disadvantages. In addition, the main factors influencing PeLED stability are identified (Fig. 1). Subsequently, different optimization strategies for film passivation and device preparation are introduced and discussed, and effective schemes are summarized. Finally, this study outlines the issues that require immediate attention and proposes potential solutions to address these issues.

This study summarizes the recent cutting-edge developments in the research on PeLED stability, summarizes the main factors affecting PeLED stability from the two perspectives of perovskite materials and LED devices, and discusses an optimization scheme based on these factors. The optimization strategy involved in this study includes the following three general objectives: film quality improvement, device structure optimization, and device thermal management. It is predicted that once the impediment of poor working stability is addressed in PeLED devices, the technology will evolve to produce a new generation of display and lighting devices with high efficiency, high color accuracy, high brightness, and low cost.