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Blue‐emitting perovskite nanocrystals (NCs) are important components of high‐definition display device, but their instability to light and moisture severely hinders the commercial application. Here, a dual‐site passivation strategy is proposed and the halogen–halogen bond to surface capping molecules is applied. The bi‐functional molecule with a fluorine group and carboxyl group on the phenyl ring, would form a shell‐like molecular structure covering the nanocrystal surface at halogen and lead site via halogen‐halogen bond and coordination effect, respectively. Considering the binding strength and acid dissociation constant of several fluoro acids, the optimal optical properties and film stability confirm the para‐fluorobenzoic acid molecule provides the most effective protection for initial perovskite products account for their stronger anchoring affinity and more comprehensive surface coverage. Consequently, this work sheds light on the molecular functionality and configuration are crucial for surface properties of perovskite NCs. [ABSTRACT FROM AUTHOR]

Mn2+ dopants introduce a new emission center in semiconductor luminescent materials, endowing them promising photoluminescence (PL) properties, such as a wide color tuning range, reversible color change, reduced self‐absorption etc. Recently, rapid development of Mn2+ doped metal halide perovskites (MHPs) promote their promising applications in displays, photovoltaics, scintillators, etc. The emission color, luminous efficiency, and energy transfer pathway of doped perovskites are affected by condition of host lattice that accommodates Mn2+ ions. In this review, the optical properties determined by host materials with diverse geometries involving perovskite nanocrystals and perovskite derivatives is focused on, and the possible energy transfer routes in different doping systems are analyzed. An overview of recent advances of different doped systems with assigned emission channels together with the influence factors, strategies to enhance PL intensity and finally potential applications are summarized. To the end, the underlying challenges and possible solutions for further research in Mn doped perovskites are proposed. [ABSTRACT FROM AUTHOR]

In the era of intelligence, the output colors of foundational phosphors are expected to be controlled by programs, while current activators‐determined afterglow candidates with fixed spectral channel have limitations in creating customized colors. Here, a long‐lived warm‐white emission is successfully demonstrated originating from self‐trapped excitons (STEs) in non‐toxic Cs2NaInCl6:Ag,Bi, ranging from 400 to 850 nm, of which the afterglow color can be easily customized using filters. This investigation indicates that 3% of Ag alloying breaks the dark STEs and introduces traps for efficient afterglow, while 3% Bi doping further improves the quantum yield to ≈100% and greatly enhances afterglow by ≈100‐fold compared with the initial intensity, allowing for an impressive afterglow persistence of over 20,000 s. Intriguingly, the self‐trapped defect bands from Jahn‐Teller distortions are prolonged from hundreds of femtoseconds to several hours, and they are first detected in the steady‐state absorption spectra after the cessation of excitation sources, contributing to the concluded dynamic afterglow model for STEs. And its intelligent application is corroborated by designed multi‐channel information system. These findings offer a novel scheme for understanding dynamic luminescence of STEs and supply an exemplification of designing white afterglow phosphors. [ABSTRACT FROM AUTHOR]

All-solution-processed perovskite light-emitting diodes (PeLEDs) with all metal oxide transport layers were successfully realized based on an ITO/NiOx/CsPbBr3/ZnMgO/Al conventional device structure. A unique perovskite–polymer composite method enables the deposition of solution-processed ZnMgO nanoparticles on the perovskite film. As a result, we achieved highly efficient PeLEDs with a maximum luminance of 17 017 cd m−2, and the efficiency showed little roll-off with increasing current density. [ABSTRACT FROM AUTHOR]

[Display omitted] • The lattice modification of Cs 2 NaInCl 6 was conducted by Ag and Zr dopants. • The emissive color temperature was tailored from warm- to cool-white with Zr content. • Double self-trapped excitons (STEs)-based pure-white afterglow was realized, which could last over 5 h. • 40 % of Zr dopants enhanced the initial afterglow intensity for ∼ 100-fold, compared with Cs 2 Na 0.9 Ag 0.1 InCl 6. • The bands of STEs were observed in steady-state absorption spectra thanks to energy storage. The incommensurable differences between the feeding and actual doping ratios of luminescent dopants and excessive reliance on rare-earth ions become two key problems in halide perovskite-based afterglow materials, restricting the production cost and further application. Here, we prepare a series of novel lead- and rare-earth-free halide afterglow phosphors Cs 2 (Na 0.9 Ag 0.1 In) 1- x Zr x Cl 6 under an ambient condition, in which the Zr dopants modify the lattice thus tailoring the emission spectrum and trap distribution, simultaneously. The focused Cs 2 (Na 0.9 Ag 0.1 In) 0.6 Zr 0.4 Cl 6 with mainly size distribution of ∼ 0.6–1.8 μm exhibits ∼ 350–850 nm ultrabroad white luminescence under ultra-violet excitation, and the introduced traps endow the white emission with a long-persistence of over 5 h after pre-irradiation. The absorption bands of self-trapped excitons (STEs) are observed in the steady-state absorption spectra during the afterglow process, suggesting the general accepted picosecond-scaled lifetimes of STEs have been successfully prolonged to hour-scale, which provide a potential opportunity for investigating the specific behavior of STEs. [ABSTRACT FROM AUTHOR]

For metal halide perovskite (MHP)‐based light‐emitting diodes (PeLEDs), effective radiative recombination of the injected holes and electrons within the MHP layer and minimized injection energy barriers at the interfaces between MHP emission layer and charge injection layers are prerequisites for high‐performance and stable PeLEDs. Herein, for the first time, novel p‐type carbon quantum dots (CQDs) are introduced as a hole injection layer in PeLEDs to replace acidic poly(3,4‐ethylenedioxythiophene):poly styrene sulfonate (PEDOT:PSS) layer. The CQDs demonstrate high hole transport mobility and desirable hole injection energy level. Moreover, the carboxyl, amine, and hydroxyl groups on CQDs not only offer a hydrophilic surface for high‐quality perovskite layer growth, but also passivate the perovskite surface defects to suppress the interfacial exciton quenching. Based on the multifunctional p‐type CQDs, high‐performance green CsPbBr3 PeLEDs with a low turn‐on voltage of only 2.8 V, maximum luminance of 25 770 cd m−2, and maximum external quantum efficiency (EQE) of 13.8% are achieved. The PeLEDs also show good operational stability and long‐term environmental stability. The first application of CQDs as a hole injection layer in PeLEDs breaks through the traditional cognition of carbon materials and opens up new pathways for the developments of carbon nanomaterials in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Quasi‐two‐dimensional (quasi‐2D) perovskites are attracting much attention due to their impressive luminescence properties. However, the introduction of insulating bulky cations reduces the charge transport property of mixed‐dimensional perovskites and leads to lowered brightness and increased turn‐on voltage. The trade‐off between high photoluminescence quantum yield (PLQY) and electrical conductivity should be well manipulated to obtain high‐performance perovskite light‐emitting diodes (PeLEDs). Herein, quasi‐2D perovskite BA2(CsPbBr3)n‐1PbBr4‐PEO with high PLQY and excellent carrier injection efficiency is demonstrated by incorporating bulky n‐butylammonium bromide (BABr), CsPbBr3, and polyethylene oxide (PEO). BA can intercalate into the three‐dimensional perovskite framework to form a layered (quasi‐2D) perovskite structure. The ion conductive polymer PEO is used to protect quasi‐2D perovskite crystals. Additional BABr is removed by using anhydrous isopropyl alcohol as a washing agent due to its selective dissolubility. By carefully modulating the optical and electrical properties of quasi‐2D perovskite films, the maximum luminance of PeLEDs is dramatically enhanced from 191 to 33533 cd m−2, which is the brightest green quasi‐2D PeLED reported thus far, leading to an increase in external quantum efficiency from 1.81% to 8.42%. This work provides a promising route to control the optical and electrical properties of quasi‐2D perovskite films for high‐performance optoelectronic devices. A quasi‐2D perovskite with high photoluminescence quantum yield and excellent carrier injection efficiency is demonstrated by incorporating n‐butylammonium bromide, CsPbBr3 and polyethylene oxide. By modulating the optical and electrical properties of quasi‐2D perovskite films, the maximum luminance of PeLEDs is dramatically enhanced from 191 to 33 533 cd m−2, which is the brightest value yet observed for green quasi‐2D PeLEDs. [ABSTRACT FROM AUTHOR]

Colloidal quantum dots light‐emitting diodes (QD‐LEDs) have been investigated for several decades. Compared with their green and red counterparts, the hole injection is more difficult for blue QDs due to their large optical band gap and relatively low highest occupied molecular orbital level. High‐performance blue QD‐LEDs are demonstrated by inserting a thin deoxyribonucleic acid (DNA) buffer layer between hole transport layer and ZnCdS/ZnS core/shell QDs layer. This DNA buffer layer can effectively enhance the hole injection efficiency, meanwhile its high lowest unoccupied molecular orbital level can help the injected electrons to be confined in the emitting layer, thus ensuring the charge balance in the QDs layer and an excellent recombination efficiency. After utilizing DNA as buffer layer, the maximum luminance is significantly increased from 10 218 to 16 655 cd m−2 and the external quantum efficiency is increased from 4.39% to 5.65%. These devices provide a saturated blue emission with emission peak located at 462 nm and full width at half maximum of 21 nm. This saturated blue emission makes it suitable for commercial applications. The results indicate that DNA is a promising material for regulating charge balance in the emitting layer for manufacturing high performance QD‐LEDs. Highly luminescent blue quantum‐dot (QD) light‐emitting diodes are successfully fabricated by introducing a thin deoxyribonucleic acid (DNA) interlayer between the hole transport layer and QDs emitting layer. The DNA buffer layer can effectively enhance the hole injection efficiency and confine the electrons in the emitting layer, thus ensuring the charge balance in the QDs layer and an excellent recombination efficiency. [ABSTRACT FROM AUTHOR]

The rice blast fungus Magnaporthe oryzae has been known to produce the phytohormone auxin/IAA from its hyphae and conidia, but the detailed biological function and biosynthesis pathway is largely unknown. By sequence homology, we identified a complete indole-3-pyruvic acid (IPA)-based IAA biosynthesis pathway in M. oryzae, consisting of the tryptophan aminotransferase (MoTam1) and the indole-3-pyruvate decarboxylase (MoIpd1). In comparison to the wild type, IAA production was significantly reduced in the motam1Δ mutant, and further reduced in the moipd1Δ mutant. Correspondingly, mycelial growth, conidiation, and pathogenicity were defective in the motam1Δ and the moipd1Δ mutants to various degrees. Targeted metabolomics analysis further confirmed the presence of a functional IPA pathway, catalyzed by MoIpd1, which contributes to IAA/auxin production in M. oryzae. Furthermore, the well-established IAA biosynthesis inhibitor, yucasin, suppressed mycelial growth, conidiation, and pathogenicity in M. oryzae. Overall, this study identified an IPA-dependent IAA synthesis pathway crucial for M. oryzae mycelial growth and pathogenic development. [ABSTRACT FROM AUTHOR]