Biomimetic non-classical crystallization induced hierarchically structured efficient circularly polarized phosphors

Abstract Hierarchically structured chiral luminescent materials hold promise for achieving efficient circularly polarized luminescence. However, a feasible chemical route to fabricate hierarchically structured chiral luminescent polycrystals is still elusive because of their complex structures and complicated formation process. We here report a biomimetic non-classical crystallization (BNCC) strategy for preparing efficient hierarchically structured chiral luminescent polycrystals using well-designed highly luminescent homochiral copper(I)-iodide hybrid clusters as basic units for biomimetic crystallization. By monitoring the crystallization process, we unravel the BNCC mechanism, which involves crystal nucleation, nanoparticles aggregation, oriented attachment, and mesoscopic transformation processes. We finally obtain the circularly polarized phosphors with both high luminescent efficiency (32%) and high luminescent dissymmetry factor (1.5 × 10-2), achieving the first demonstration of a circularly polarized phosphor converted light emitting diode with a polarization degree of 1.84% at room temperature. Our designed BNCC strategy provides a simple, reliable and large-scale synthetic route for preparing bright circularly polarized phosphors.

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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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(Invited) High Brightness, Large Scale GaN Based Light-Emitting Diode Grown on 8-Inch Si Substrate

ECS Transactions ◽

10.1149/06104.0071ecst ◽

2014 ◽

Vol 61 (4) ◽

pp. 71-78

Author(s):

S.-J. Lee ◽

H.-J. Park ◽

J.-B. Park ◽

D.-W. Jeon ◽

J. H. Baek ◽

...

Keyword(s):

Large Scale ◽

Light Emitting Diode ◽

Si Substrate ◽

High Brightness ◽

Light Emitting

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Theoretical study on the light-emitting mechanism of circularly polarized luminescence molecules with both thermally activated delayed fluorescence and aggregation-induced emission

Physical Chemistry Chemical Physics ◽

10.1039/c9cp00402e ◽

2019 ◽

Vol 21 (14) ◽

pp. 7288-7297 ◽

Cited By ~ 6

Author(s):

Xiu Yin ◽

Jian-Zhong Fan ◽

Jie Liu ◽

Lei Cai ◽

Hao Sun ◽

...

Keyword(s):

Theoretical Study ◽

Delayed Fluorescence ◽

Thermally Activated Delayed Fluorescence ◽

Light Emitting ◽

Circularly Polarized ◽

Aggregation Induced Emission ◽

Thermally Activated ◽

Circularly Polarized Luminescence ◽

Polarized Luminescence

The light-emitting mechanism of circularly polarized luminescence molecules with both TADF and AIE.

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Design of Light Emitting Diodes (LEDs) Lighting System and Its Application in Garden Landscape Decoration

Journal of Nanoelectronics and Optoelectronics ◽

10.1166/jno.2020.2793 ◽

2020 ◽

Vol 15 (6) ◽

pp. 734-742

Author(s):

Hailiang Liu ◽

Jiade Cheng ◽

Asnidar Hanim Yusuf

Keyword(s):

Control System ◽

Large Scale ◽

Light Emitting Diode ◽

Image Data ◽

Junction Temperature ◽

Lighting System ◽

Light Emitting ◽

Led Lighting ◽

Arm Processor ◽

Control Node

Light Emitting Diode (LED) is widely used in garden landscape decoration because of its small size, low power, concentrated light, and the capability of showing more vivid colors. While designing the LED lighting system, considering that a single Advanced RISC Machine (ARM)-based control system cannot achieve large-scale LED display, and a single Field Programmable Gate Array (FPGA)-based control system cannot control the lighting system well, an LED system with the combination of ARM processor-FPGA is proposed. In this system, the ARM processor is used as the major control component. The Linux system realizes remote monitoring and intelligent management of image data. In addition, FPGA is used for LED data output. The lighting system consists of a major control node and a lighting node. The nodes are connected in parallel through a chain network. The major control node uses an ARM Cortex processor and is equipped with a Linux operating system. The lighting node uses ARM + FPGA hardware architecture. During the experiments, the LED lighting system is tested first. The results show that the reading and writing speed is fast. The LED display screen meets the lighting requirements. This LED lighting system is used for night lighting of garden landscapes. During the brightness test, the brightness of lighting objects and the background is used as research objects. Experiments have proved that the ratio of the lighting object brightness to the background brightness between (Yu, M. and Li, X., 2012. A little current k-factor method for measuring junction temperature of aviation lighting power led. Guangxue Jishu/Optical Technique, 38(3), pp.371–375; Monas, A., Verma, A., Gawari, A. and Paswan, R. S., 2016. Portable network monitor using arm processor. Procedia Computer Science, 92, pp.493–497.) is suitable for night lighting of garden landscape decoration, which will not bring discomfort to people who enjoy night scenery.

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Dual Stimuli-Responsive High-Efficiency Circularly Polarized Luminescence from Light-Emitting Chiral Nematic Liquid Crystals

ACS Applied Materials & Interfaces ◽

10.1021/acsami.0c17241 ◽

2020 ◽

Vol 12 (50) ◽

pp. 56604-56614

Author(s):

Youde Chen ◽

Peng Lu ◽

Zhiyan Li ◽

Yongjie Yuan ◽

Qiang Ye ◽

...

Keyword(s):

Liquid Crystals ◽

High Efficiency ◽

Nematic Liquid Crystals ◽

Stimuli Responsive ◽

Light Emitting ◽

Circularly Polarized ◽

Chiral Nematic ◽

Circularly Polarized Luminescence ◽

Polarized Luminescence

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Control Measures for SARS-CoV-2: A Review on Light-Based Inactivation of Single-Stranded RNA Viruses

Pathogens ◽

10.3390/pathogens9090737 ◽

2020 ◽

Vol 9 (9) ◽

pp. 737 ◽

Cited By ~ 1

Author(s):

Joshua Hadi ◽

Magdalena Dunowska ◽

Shuyan Wu ◽

Gale Brightwell

Keyword(s):

Large Scale ◽

Rna Virus ◽

Light Emitting Diode ◽

Red Light ◽

Ultrashort Pulses ◽

Control Measures ◽

Pulsed Light ◽

Light Emitting ◽

The Family ◽

Modelling Studies

SARS-CoV-2 is a single-stranded RNA virus classified in the family Coronaviridae. In this review, we summarize the literature on light-based (UV, blue, and red lights) sanitization methods for the inactivation of ssRNA viruses in different matrixes (air, liquid, and solid). The rate of inactivation of ssRNA viruses in liquid was higher than in air, whereas inactivation on solid surfaces varied with the type of surface. The efficacy of light-based inactivation was reduced by the presence of absorptive materials. Several technologies can be used to deliver light, including mercury lamp (conventional UV), excimer lamp (UV), pulsed-light, and light-emitting diode (LED). Pulsed-light technologies could inactivate viruses more quickly than conventional UV-C lamps. Large-scale use of germicidal LED is dependent on future improvements in their energy efficiency. Blue light possesses virucidal potential in the presence of exogenous photosensitizers, although femtosecond laser (ultrashort pulses) can be used to circumvent the need for photosensitizers. Red light can be combined with methylene blue for application in medical settings, especially for sanitization of blood products. Future modelling studies are required to establish clearer parameters for assessing susceptibility of viruses to light-based inactivation. There is considerable scope for improvement in the current germicidal light-based technologies and practices.

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Development and Property Investigation of a Large-Scale Strain Sensor by Grating Moiré Fringe Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.718-720.1383 ◽

2013 ◽

Vol 718-720 ◽

pp. 1383-1387

Author(s):

Cheng Li Duan ◽

Ya Dong Jiang ◽

Li Jie Chen ◽

Hui Ling Tai

Keyword(s):

Solid State ◽

Large Scale ◽

Near Infrared ◽

Light Emitting Diode ◽

Processing System ◽

Strain Sensor ◽

Strain Sensitivity ◽

Signal Processing System ◽

Light Emitting ◽

Photodiode Array

A large-scale strain sensor for measuring the strain between 0~0.2ε has been developed using grating moiré fringe in this work. The gallium arsenide near-infrared solid-state light-emitting diode was used for light source of the sensor, and photodiode array sensor was chosen for the photodetector. The signal received was converted into digital pulses for the output by the signal processing system and displayed. The results indicated that the fabricated large-scale strain sensor showed the good linearity and repeatability, and low hysteresis. Strain sensitivity of 620ε-1 and a minimum strain of 0.004 ε can be achieved.

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