Low-dose real-time X-ray imaging with nontoxic double perovskite scintillators

Light Science & Applications, Journal Year: 2020, Volume and Issue: 9(1)

Published: June 30, 2020

X-rays are widely used in probing inside information nondestructively, enabling broad applications the medical radiography and electronic industries. X-ray imaging based on emerging lead halide perovskite scintillators has received extensive attention recently. However, strong self-absorption, relatively low light yield toxicity of these perovskites restrict their practical applications. Here, we report a series nontoxic double-perovskite Cs

Language: Английский

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Sb³⁺ Dopant and Halogen Substitution Triggered Highly Efficient and Tunable Emission in Lead-Free Metal Halide Single Crystals

Chemistry of Materials, Journal Year: 2020, Volume and Issue: 32(12), P. 5327 - 5334

Published: May 15, 2020

Rational doping and compositional control remain significant challenges in designing luminescent metal halides to achieve highly efficient tunable emission. Here, the air-stable lead-free Cs2InCl5·H2O crystal with a zero-dimensional structure was investigated as pristine compound design new luminescence materials. Sb3+-doping Cs2InCl5·H2O:Sb3+ enabled broadband yellow emission photoluminescence quantum yield up 95.5%. The colors can be expanded into orange-red region by halogen substitution for Cs2InX5·H2O:Sb3+ (X = Cl/Br/I). optical characterizations along theoretical calculations demonstrate that characteristic singlet triplet self-trapped exciton emissions of ns2-metal-halide centers account luminescence. Moreover, admirable stability against air heat pave way its further applications white light-emitting diodes high-resolution fluorescent signs anticounterfeiting technology. Our achievement case Sb3+-doped represents successful strategy developing stable versatile applications.

Language: Английский

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Colloidal Synthesis of Ternary Copper Halide Nanocrystals for High-Efficiency Deep-Blue Light-Emitting Diodes with a Half-Lifetime above 100 h

Nano Letters, Journal Year: 2020, Volume and Issue: 20(5), P. 3568 - 3576

Published: April 3, 2020

Currently, the blue perovskite light-emitting diodes (PeLEDs) suffer from a compromise in lead toxicity and poor operation stability, most previous studies have struggled to meet crucial NTSC standard. In this study, electrically driven deep-blue LEDs (∼445 nm) based on zero-dimensional (0D) Cs3Cu2I5 nanocrystals (NCs) were demonstrated with color coordinates of (0.16, 0.07) high external quantum efficiency ∼1.12%, comparable best-performing lead-halide perovskites. Encouraged by remarkable stability NCs against heat environmental oxygen/moisture, proposed device was operated continuous current mode for 170 h, producing record half-lifetime ∼108 h. The further verified an aggressive thermal cycling test (300–360–300 K) 35-day storage test. Together eco-friendly features facile colloidal synthesis technique, 0D can be therefore regarded as promising candidate applications.

Language: Английский

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High Color‐Rendering Index and Stable White Light‐Emitting Diodes by Assembling Two Broadband Emissive Self‐Trapped Excitons

Advanced Materials, Journal Year: 2020, Volume and Issue: 33(2)

Published: Nov. 23, 2020

Abstract White light‐emitting diodes (WLEDs) are promising next‐generation solid‐state light sources. However, the commercialization route for WLED production suffers from challenges in terms of insufficient color‐rendering index (CRI), color instability, and incorporation rare‐earth elements. Herein, a new two‐component strategy is developed by assembling two broadband emissive materials with self‐trapped excitons (STEs) high CRI stable WLEDs. The addresses effectively challenging issues facing current Based on first‐principles thermodynamic calculations, copper‐based ternary halides composites, CsCu 2 I 3 @Cs Cu 5 , synthesized facile one‐step solution approach. composites exhibit an ideal white‐light emission cold/warm tuning robust stability against heat, ultraviolet light, environmental oxygen/moisture. A series tunable WLEDs demonstrated maximum luminance 145 cd m −2 external quantum efficiency 0.15%, record 91.6 achieved, which highest value lead‐free Importantly, fabricated device demonstrates excellent operation continuous mode, exhibiting long half‐lifetime 238.5 min. results promise use hybrids STEs‐derived high‐performance

Language: Английский

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Stable Yellow Light-Emitting Devices Based on Ternary Copper Halides with Broadband Emissive Self-Trapped Excitons

ACS Nano, Journal Year: 2020, Volume and Issue: 14(4), P. 4475 - 4486

Published: March 13, 2020

Great successes have been achieved in developing perovskite light-emitting devices (LEDs) with blue, green, red, and near-infrared emissions. However, as key optoelectronic devices, yellow-colored LEDs remain challenging, mainly due to the inevitable halide separation mixed perovskites under high bias, causing undesired color change of devices. In addition this color-missing problem, intrinsic toxicity poor stability conventional lead-halide also restrict their practical applications. We herein report fabrication stable yellow based on a ternary copper CsCu2I3, addressing instability issues facing current LED's compromise. Joint experiment-theory characterizations indicate that electroluminescence originates from broadband emission self-trapped excitons centered at 550 nm well comparable reasonably low carrier effective masses favorable for charge transport. With maximum luminance 47.5 cd/m2 an external quantum efficiency 0.17%, fabricated exhibit long half-lifetime 5.2 h 25 °C still function properly 60 2.2 h, which benefits superior resistance CsCu2I3 heat, moisture, oxidation ambient environmental conditions. The results obtained promise halides light environment-friendly emitter compatible

Language: Английский

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Lead‐Free Halide Perovskites for Light Emission: Recent Advances and Perspectives

Advanced Science, Journal Year: 2021, Volume and Issue: 8(4)

Published: Jan. 4, 2021

Abstract Lead‐based halide perovskites have received great attention in light‐emitting applications due to their excellent properties, including high photoluminescence quantum yield (PLQY), tunable emission wavelength, and facile solution preparation. In spite of characteristics, the presence toxic element lead directly obstructs further commercial development. Hence, exploiting lead‐free perovskite materials with superior properties is urgent necessary. this review, deep‐seated reasons that benefit light for perovskites, which help develop performance, are first emphasized. Recent advances (single crystals, thin films, nanocrystals different dimensionalities) from synthesis, crystal structures, optical optoelectronic then systematically summarized. particular, phosphor‐converted LEDs electroluminescent using fully examined. Ultimately, based on current development future directions terms devices discussed.

Language: Английский

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Photoluminescence of Singlet/Triplet Self‐Trapped Excitons in Sb³⁺‐Based Metal Halides

Advanced Optical Materials, Journal Year: 2021, Volume and Issue: 9(8)

Published: Feb. 18, 2021

Abstract Emerging lead‐free metal halides with low toxicity and unparalleled optoelectronic properties have attracted growing research interests, also demonstrating extensive application potentials. Among these, Sb 3+ ‐based all‐inorganic/organic–inorganic hybrid become a vital group due to the special energy level distribution along diverse optical properties. However, there remains gap in understanding relationship between crystal structure radiation process of involved emission. Herein, existing reports about luminescent are revisited their structure–luminescence–application is explored, it further established that triplet self‐trapped excitons (STEs) emission varies different crystallographic environments endows tunable performance. This work aims provide constructive strategies exploitation halides, guides structural design photoluminescence tuning doped halide materials.

Language: Английский

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An Overview for Zero‐Dimensional Broadband Emissive Metal‐Halide Single Crystals

Advanced Optical Materials, Journal Year: 2021, Volume and Issue: 9(17)

Published: May 31, 2021

Abstract The high‐profile candidacy of low‐dimensional metal‐halide single crystals as promising light emitters originates from the intriguing emission properties (e.g., extremely broad luminescence spectra, large Stokes shift, high color rendition), which have enabled recent great achievements on their application in lighting, artificial illumination, and scintillators. Among family crystals, zero‐dimensional (0D) materials been featured lowest dimensionality, a consequence, strongest quantum confinement, softest lattice, electron–phonon coupling further translated into near‐unity photoluminescence (PL) efficiency with broadband emission. However, far it is known, 0D structures are significantly underexplored. Herein, an overview provided advances focus comprehensive understanding insightful perspectives behind photophysical mechanism. Additionally, challenges future opportunities currently faced by bulk metal halides discussed order to provide roadmap for development novel versatile optical suited practical applications.

Language: Английский

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Facet‐Dependent, Fast Response, and Broadband Photodetector Based on Highly Stable All‐Inorganic CsCu₂I₃ Single Crystal with 1D Electronic Structure

Advanced Functional Materials, Journal Year: 2020, Volume and Issue: 30(28)

Published: May 13, 2020

Abstract Low‐dimensional metal halides at molecular level, which feature strong quantum confinement effects from intrinsic structure, are emerging as ideal candidates in optoelectronic fields. However, developing stable and nontoxic still remains a great challenge. Herein, for the first time, high‐crystalline highly CsCu 2 I 3 single crystal, is acquired by low‐cost antisolvent vapor assisted method, successfully developed to construct high‐speed ( t rise / decay = 0.19 ms/14.7 ms) UV‐to‐visible broadband (300–700 nm) photodetector, outperforming most reported photodetectors based on individual all‐inorganic lead‐free halides. Intriguingly, facet‐dependent photoresponse observed whose morphology consists of {010}, {110}, {021} crystal planes. The on–off ratio {010} plane higher than that {110} plane, mainly owing lower dark current. Furthermore, photogenerated electrons localized twofold chains created [CuI 4 ] tetrahedra, leading relatively small effective mass fast transport mobility along 1D pathway. Anisotropic carrier characteristic related stronger electron density This work not only demonstrates potential high‐performance optoelectronics, but also gives insights into electronic structure associated with high anisotropy.

Language: Английский

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Room Temperature Synthesis of Stable, Printable Cs₃Cu₂X₅ (X = I, Br/I, Br, Br/Cl, Cl) Colloidal Nanocrystals with Near-Unity Quantum Yield Green Emitters (X = Cl)

Chemistry of Materials, Journal Year: 2020, Volume and Issue: 32(13), P. 5515 - 5524

Published: June 9, 2020

Lead halide perovskite nanocrystals (NCs) have shown remarkable properties for emission applications, but their toxicity and instability are a hindrance to many commercial uses. Herein, we report the synthesis of lead-free all-inorganic Cs3Cu2X5 (X = I, Br/I, Br, Br/Cl, Cl) colloidal as members metal–metal family materials. These uniform sizes less than 10 nm in diameter show excellent optical properties, including composition-tunable spectra over spectral region 440–530 nm; high photoluminescence quantum yields ∼100, 20, 30% X Cl, respectively; large effective Stokes shifts 100 all species. Nanocrystals synthesized by room temperature, antisolvent method, precursors ligands also be hot -injection synthesis. Pure- mixed-halide materials tunable with concentration, fwhm 80–110 due widely reported exciton self-trapping mechanism. Notably, Cu3Cu2Cl5 NCs exhibit near-unity yield an at 520 nm, crystallinity, good stability. can processed maintained adequately stable dispersions enable inkjet printing these into arbitrary patterns. results indicate that cesium copper chloride may great potential future display or lighting applications.

Language: Английский

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