Metal Halide Perovskites for Red‐Emission Light‐Emitting Diodes

Abstract

Metal halide perovskites (MHPs) exhibit remarkable optoelectronic properties, thus attracting widespread attention. Over the last several years, the external quantum efficiencies of perovskite light‐emitting diodes (PeLEDs) have exceeded 20%. Despite great progresses have been made, it remains challenging to realize high performance and stable PeLEDs. Especially, red‐emission PeLEDs still cannot meet the requirement of Rec. 2100 standard. Understanding the relationship between perovskite structure and their photophysical properties will greatly facilitate the development of PeLEDs. In this review, the structural and photophysical properties of MHPs are summarized, emphasizing three archetypes (CsPbI3, FAPbI3, and MAPbI3) of perovskites for red emission. Based on the fundamental characteristics, the recently emerged optical property modulation for obtaining high‐quality red‐emission perovskite films is outlined. Then, the approaches to optimizing electronics property and extending the operational lifetime of red‐emission PeLEDs are summarized. Finally, an outlook on the future challenges and potential directions toward red‐emission PeLEDs is represented.

Solvent-Free Grinding Synthesis of Hybrid Copper Halides for White Light Emission

“…Because of their large Stokes shifts, broadband emissive range, and nontoxicity, lead-free metal halides (LMHs) have been considered as potential candidates for efficient emitters in WLEDs. − Among a variety of LMHs, copper halides have received a lot of attention due to their outstanding optoelectronic properties induced from the formation of self-trapped excitons (STEs), including negligible self-absorption and broadband emission. ,− They may facilitate high efficiency and high color rendering index (CRI) values of as-fabricated WLEDs. Huang et al synthesized stable CsCu 2 I 3 perovskite single crystals with an emission peak of 568 nm and a photoluminescence quantum yield (PLQY) of 15.7% via an antisolvent infiltration method .…”

Spacer cation engineering in Ruddlesden-Popper perovskites for efficient red light-emitting diodes with recommendation 2020 color coordinates

“…Nevertheless, high-performance red PeLEDs with Rec. 2020 color coordinates are rarely reported, probably due to the challenge of attaining reasonable control over the properties of RPP films [31]. Currently, the RPP films are mainly modulated by precursor regulation, additives, and co-spacer engineering [6,7,29,32,33].…”

In Situ Halide Insertion for Efficient and Stable Pure‐Red Perovskite Light‐Emitting Diodes

“…To achieve the desirable pure-red perovskite emitters, substantial progress has been made in the modulation of the perovskite composition and dimensionality. [15,16] In the aspect of perovskite composition, the strategy of mixed-halide perovskites (e.g., CsPbBr x I 3-x , FAPbBr x I 3-x , 0 < x < 3, FA: formamidinium) were widely adopted to obtain the desired emission colors. The emission wavelengths of mixed bromide-iodine perovskite can be facilely tuned to achieve purered emission by optimizing the bromide/iodine ratio.…”