Blue perovskite LEDs: A comprehensive review of emission control strategies for enhanced performance

Blue light-emitting diodes (LEDs) play a crucial role in full-color displays, with blue perovskite materials emerging as promising candidates for blue LEDs. However, the development of blue perovskite LEDs remains relatively limited, particularly regarding the precise regulation of color purity, or emission wavelength. In this review, we categorize the blue light-emitting region based on the standard wavelength (465 nm) defined by the Commission Internationale de l'Eclairage (CIE), dividing it into two segments: short wavelengths (405–465 nm) and long wavelengths (466–495 nm). We then discuss the latest advancements in blue perovskite LEDs across different dimensional structures (3D and 2D), highlighting strategies such as size control, ion doping, and anion exchange to fine-tune the emission wavelength within the specified regions. Furthermore, we summarize methods to enhance the quality of perovskite films and minimize non-radiative recombination, including improvements to the hole transport layer and in-situ passivation techniques. Finally, we outline the current challenges in the field and present future perspectives aimed at inspiring new insights into blue perovskite LEDs research, providing guidance for active researchers in this area.