Controllable Synthesis of All Inorganic Lead Halide Perovskite Nanocrystals with Various Appearances in Multiligand Reaction System

All inorganic cesium lead halide (CsPbX3, X = Cl, Br, I) perovskite nanocrystals (PNCs) exhibit promising applications in light-emitting devices due to their excellent photophysical properties. Herein, we developed a low-cost and convenient method for the preparation of CsPbX3 PNCs in a multiligand-assisted reaction system where peanut oil is applied as a ligand source. The mixed-halide PNCs with tunable optical-band gap were prepared by mixing the single-halide perovskite solutions at room temperature. The resulting PNCs had good monodispersity, with dimensions of 8–10 nm, high photoluminescence quantum yield (96.9%), narrow emission widths (15–34 nm), and tunable emission wavelength (408–694 nm), covering the entire visible spectrum. Additionally, various morphologies of PNCs, such as nanospheres, nanocubes, and nanowires, were obtained by controlling reaction temperature and time, and the amount of oleamine with multiple ligands in peanut oil potentially playing a dominant role in the nucleation/growth processes of our PNCs. Finally, the resulting CsPbBr3 PNCs were employed to develop a white light-emitting diode (WLED), demonstrating the potential lighting applications for our method.

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Near Unity PLQY and High Stability of Barium Thiocyanate Based All-Inorganic Perovskites and Their Applications in White Light-Emitting Diodes

Photonics ◽

10.3390/photonics8060209 ◽

2021 ◽

Vol 8 (6) ◽

pp. 209

Author(s):

Gopi Chandra Adhikari ◽

Saroj Thapa ◽

Yang Yue ◽

Hongyang Zhu ◽

Peifen Zhu

Keyword(s):

White Light ◽

Large Scale ◽

Light Emitting Diode ◽

Photophysical Properties ◽

Environmental Stability ◽

Color Temperature ◽

Ambient Atmosphere ◽

Light Emitting ◽

Halide Perovskite ◽

Lead Halide

All-inorganic lead halide perovskite (CsPbX3) nanocrystals (NCs) have emerged as a highly promising new generation of light emitters due to their extraordinary photophysical properties. However, the performance of these semiconducting NCs is undermined due to the inherent toxicity of lead and long-term environmental stability. Here, we report the addition of B-site cation and X-site anion (pseudo-halide) concurrently using Ba(SCN)2 (≤50%) in CsPbX3 NCs to reduce the lead and improve the photophysical properties and stability. The as-grown particles demonstrated an analogous structure with an almost identical lattice constant and a fluctuation of particle size without altering the morphology of particles. Photoluminescence quantum yield is enhanced up to near unity (~98%) by taking advantage of concomitant doping at the B- and X-site of the structure. Benefitted from the defect reductions and stronger bonding interaction between Pb2+ and SCN− ions, Ba(SCN)2-based NCs exhibit improved stability towards air and moisture compared to the host NCs. The doped NCs retain higher PLQY (as high as seven times) compared to the host NCs) when stored in an ambient atmosphere for more than 176 days. A novel 3D-printed multiplex color conversion layer was used to fabricate a white light-emitting diode (LED). The obtained white light shows a correlated color temperature of 6764 K, a color rendering index of 87, and luminous efficacy of radiation of 333 lm/W. In summary, this work proposes a facile route to treat sensitive lead halide perovskite NCs and to fabricate LEDs by using a low-cost large-scale 3-D printing method, which would serve as a foundation for fabricating high-quality optoelectronic devices for near future lighting technologies.

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Impurity Ions Codoped Cesium Lead Halide Perovskite Nanocrystals with Bright White Light Emission toward Ultraviolet–White Light-Emitting Diode

ACS Applied Materials & Interfaces ◽

10.1021/acsami.8b14275 ◽

2018 ◽

Vol 10 (45) ◽

pp. 39040-39048 ◽

Cited By ~ 33

Author(s):

Gencai Pan ◽

Xue Bai ◽

Wen Xu ◽

Xu Chen ◽

Donglei Zhou ◽

...

Keyword(s):

White Light ◽

Light Emission ◽

Light Emitting Diode ◽

White Light Emission ◽

Light Emitting ◽

Perovskite Nanocrystals ◽

Impurity Ions ◽

Bright White Light ◽

Halide Perovskite ◽

Lead Halide

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Hollow metal halide perovskite nanocrystals with efficient blue emissions

Science Advances ◽

10.1126/sciadv.aaz5961 ◽

2020 ◽

Vol 6 (17) ◽

pp. eaaz5961 ◽

Cited By ~ 4

Author(s):

Michael Worku ◽

Yu Tian ◽

Chenkun Zhou ◽

Haoran Lin ◽

Maya Chaaban ◽

...

Keyword(s):

Quantum Confinement Effect ◽

Visible Spectrum ◽

Precursor Solution ◽

Metal Halide ◽

Synthetic Control ◽

Light Emitting ◽

Perovskite Nanocrystals ◽

Highly Efficient ◽

Metal Halide Perovskite ◽

Halide Perovskite

Metal halide perovskite nanocrystals (NCs) have emerged as new-generation light-emitting materials with narrow emissions and high photoluminescence quantum efficiencies (PLQEs). Various types of perovskite NCs, e.g., platelets, wires, and cubes, have been discovered to exhibit tunable emissions across the whole visible spectrum. Despite remarkable advances in the field of perovskite NCs, many nanostructures in inorganic NCs have not yet been realized in metal halide perovskites, and producing highly efficient blue-emitting perovskite NCs remains challenging and of great interest. Here, we report the discovery of highly efficient blue-emitting cesium lead bromide (CsPbBr3) perovskite hollow NCs. By facile solution processing of CsPbBr3 precursor solution containing ethylenediammonium bromide and sodium bromide, in situ formation of hollow CsPbBr3 NCs with controlled particle and pore sizes is realized. Synthetic control of hollow nanostructures with quantum confinement effect results in color tuning of CsPbBr3 NCs from green to blue, with high PLQEs of up to 81%.

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