Operational and Spectral Stability of Perovskite Light-Emitting Diodes

Abstract

As an emerging light source, perovskite light-emitting diodes (PeLEDs) based on metal halide perovskites have witnessed incredible progress in recent years, and device efficiency is considerably enhanced toward the level of practical applications. However, the stability of the PeLEDs is significantly behind that of commercial light sources. It is imminent to considerably improve the operational stability of the device. In this Review, we first analyze the factors that cause device degradation. Then, we describe the research progress in improving PeLEDs’ operational stability via defect passivation, charge balance, and thermal management. Furthermore, the issue of spectral stability is presented. Finally, we discuss the future development directions for achieving high-performing and stable PeLEDs.

Mg2+-Assisted Passivation of Defects in CsPbI3 Perovskite Nanocrystals for High-Efficiency Photoluminescence

“…To improve the stability of the NCs, a common method was used to strengthen surface binding energy of NCs through ligand modification. 10 Usually, long-chain ligands such as oleylamine (OLA) and oleic acid (OA) are easily detached from the surface of NCs during the purification process, which leads to poor stability. It is reported that optical properties and stability of CsPbI 3 NCs in harsh environments can be improved by using short-chain ligands or ligands with multiple functional groups, such as hexamethyldisilathiane (HMS), sodium dodecyl sulfate (SDS), didodecyldimethylammonium bromide (DDAB), 2,2′-iminodibenzoic acid (IDA), 11−14 etc.…”

“…Note that the CsPbI 3 is easy to transform from the cubic phase (α) to the nonluminescent perovskite phase (δ) at room temperature because of the intrinsic properties of the crystal structure with low formation energy, tolerance factor, and migration activation energy. − The intrinsic chemical instability of CsPbI 3 NCs seriously limits their practical application. To improve the stability of the NCs, a common method was used to strengthen surface binding energy of NCs through ligand modification . Usually, long-chain ligands such as oleylamine (OLA) and oleic acid (OA) are easily detached from the surface of NCs during the purification process, which leads to poor stability.…”

Precipitation of cesium lead halide perovskite nanocrystals in glasses based on liquid phase separation

“…Inorganic cesium lead halide (CsPbX 3 , X = Cl, Br, I) perovskite nanocrystals (PNCs) have many interesting opto-electronic properties, [1][2][3][4][5][6][7][8] and are promising for applications in the field of light emitting diodes, 9,10 energy harvesting, 11 gain media, 12 etc. In recent years, controlled synthesis of CsPbX 3 PNCs has been realized via hot injection, ligand-assisted reprecipitation, ion-exchange, solvothermal, ultrasonication, and molten salt methods.…”

Anti-Stokes Photoluminescence Regulated by Lattice Distortion of CsPbX3 Nanocrystals in Glasses

“…All-inorganic CsPbX 3 (X = Cl, Br, and I) nanocrystals (NCs) have attracted extensive attention due to their extraordinary optoelectronic properties. − However, their applications in the fields of solar cells, light-emitting diodes, , and lasers are substantially affected by the poor resistance to temperature, humidity, radiation, and so forth . A lot of strategies and efforts have been implemented to improve this shortcoming to a certain extent, such as surface modification, element doping, core–shell structuring, and wrapping with stable media (such as mesoporous SiO 2 or poly­(methyl methacrylate)). − Incorporation of semiconductor NCs into glasses has been considered as one of the effective ways to improve the stabilities of the NCs since the dense and inert structure of glasses are stable and keep these NCs safe from the harsh environment. − In 2016, just 1 year after the preparation of colloidal CsPbX 3 NCs by Protesescu’s team, Ai et al successfully precipitated CsPbBr 3 NCs in phosphate glass with the tunable absorption and photoluminescence (PL) in the visible spectral range, demonstrating the feasibility of the incorporation of CsPbX 3 NCs into glasses .…”

“…All-inorganic CsPbX 3 (X = Cl, Br, and I) nanocrystals (NCs) have attracted extensive attention due to their extraordinary optoelectronic properties. 1−5 However, their applications in the fields of solar cells, 6 light-emitting diodes, 7,8 and lasers 9 are substantially affected by the poor resistance to temperature, humidity, radiation, and so forth. 10 A lot of strategies and efforts have been implemented to improve this shortcoming to a certain extent, such as surface modification, 11 element doping, 12 core−shell structuring, and wrapping with stable media (such as mesoporous SiO 2 or poly(methyl methacrylate)).…”