scholarly journals Remarkable photoluminescence enhancement of CsPbBr3 perovskite quantum dots assisted by metallic thin films

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenchao Zhao ◽  
Zhengji Wen ◽  
Qianqian Xu ◽  
Ziji Zhou ◽  
Shimin Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Quantum Dots ◽  
Quantum Efficiency ◽  
Light Emission ◽  
Luminescent Properties ◽  
Dielectric Substrate ◽  
Excitation Wavelength ◽  
Metallic Thin Films ◽  
Fabry Perot ◽  
Perovskite Quantum Dots

Abstract All-inorganic cesium lead halide perovskite quantum dots have recently received much attention as promising optoelectronic materials with great luminescent properties and bright application prospect in lighting, lasing, and photodetection. Although notable progress has been achieved in lighting applications based on such media, the performance could still be improved. Here, we demonstrate that the light emission from the perovskite QDs that possess high intrinsic luminous efficiency can be greatly enhanced by using metallic thin films, a technique that was usually considered only useful for improving the emission of materials with low intrinsic quantum efficiency. Eleven-fold maximal PL enhancement is observed with respect to the emission of perovskite QDs on the bare dielectric substrate. We explore this remarkable enhancement of the light emission originating from the joint effects of enhancing the incident photonic absorption of QDs at the excitation wavelength by means of the zero-order optical asymmetric Fabry–Perot-like thin film interference and increasing the radiative rate and quantum efficiency at the emission wavelength mediated by surface plasmon polaritons. We believe that our approach is also potentially valuable for the enhancement of light emission of other fluorescent media with high intrinsic quantum efficiency.

scholarly journals Fabrication of Thin Films from Powdered Cesium Lead Bromide (CsPbBr3) Perovskite Quantum Dots for Coherent Green Light Emission

ACS Omega ◽  
2020 ◽  
Vol 5 (46) ◽  
pp. 30111-30122 ◽  
Author(s):  
Saif M. H. Qaid ◽  
Hamid M. Ghaithan ◽  
Bandar Ali Al-Asbahi ◽  
Abdulaziz Alqasem ◽  
Abdullah S. Aldwayyan
Keyword(s):  
Thin Films ◽  
Quantum Dots ◽  
Light Emission ◽  
Green Light ◽  
Green Light Emission ◽  
Lead Bromide ◽  
Perovskite Quantum Dots

scholarly journals Facile and High-yield Synthesis of N-doped Carbon Quantum Dots from Biomass Quinoa Saponin for the Detection of Co2+

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Cuo Zhou ◽  
Shunwei Wu ◽  
Shenghui Qi ◽  
Weijun Song ◽  
Chunyan Sun
Keyword(s):  
Quantum Dots ◽  
Metal Ion ◽  
Light Emission ◽  
Low Cost ◽  
Carbon Quantum Dots ◽  
High Yield ◽  
Excitation Wavelength ◽  
Uniform Size ◽  
Orthogonal Experiments ◽  
Co2 Detection

Hydrothermal synthesis of carbon quantum dots (CQDs) from natural biomass is a green and sustainable route for CQDs applications in various fields. In this work, the preparation and characterization of CQDs based on quinoa saponin were investigated. The optimum synthetic conditions determined by orthogonal experiments were as follows: 2 g quinoa saponin powder and 0.04 mol ethylenediamine reacted at 200°C for 10 h. The relative fluorescence quantum yield (QY = 22.2%) can be obtained, which is higher than some results reported in the literatures. The prepared CQDs had a small and uniform size (∼2.25 nm) and exhibited excitation wavelength-dependent blue light emission behavior. The CQDs displayed excellent sensitivity for Co2+ detection along with good linear correlation ranging from 20 to 150 µM and the detection limit of 0.49 µM. The CQDs prepared in this experiment were successfully implanted into soybean sprouts for fluorescence imaging. The sprouts could grow healthily even soaked in the CQDs solution for two weeks, demonstrating the low toxicity of the CQDs. The advantages of the CQDs, such as low cost, ease of manufacture, nontoxicity, and stability, have potential applications in many areas such as metal ion detection and biosensing.

Photoluminescence quenching of inorganic cesium lead halides perovskite quantum dots (CsPbX3) by electron/hole acceptor

2017 ◽  
Vol 19 (3) ◽  
pp. 1920-1926 ◽  
Author(s):  
Yan-Xia Zhang ◽  
Hai-Yu Wang ◽  
Zhen-Yu Zhang ◽  
Yu Zhang ◽  
Chun Sun ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement ◽  
Light Emission ◽  
Confinement Effects ◽  
Recombination Rates ◽  
Photoluminescence Quenching ◽  
Electron Hole ◽  
Carrier Recombination ◽  
Quantum Confinement Effects ◽  
Perovskite Quantum Dots

CsPbBr3 QDs with smaller size showed faster carrier recombination rates and PL decay lifetimes due to their relatively stronger quantum confinement effects, which may be useful for applications in photovoltaic and light emission devices.

Stable CsPbX3@SiO2 Perovskite Quantum Dots for White-Light Emitting Diodes

2020 ◽  
Vol 15 (5) ◽  
pp. 599-606
Author(s):  
Jian Xu ◽  
Hongxiang Zhang ◽  
Chunxia Wu ◽  
Jun Dai
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Synthesis Method ◽  
Water Contact ◽  
Light Emitting ◽  
Perovskite Quantum Dots ◽  
The Stability ◽  
White Light Emitting Diodes

In this article, we reported the synthesis method of stable CsPbX3@SiO2 quantum dots using cesium acetate instead of cesium carbonate. The results showed that CsPbX3@SiO2 presents good crystallinity and excellent luminescence properties. The coating layer of SiO2 on the CsPbX3 quantum dots surface blocks the air and water contact and suppresses anion exchange between the quantum dots, which dramatically enhances the stability. White light-emitting diode devices are manufactured by integrating the green CsPbBr3@SiO2 quantum dots and red CsPbBr1 I2@SiO2 quantum dots on the blue GaN chips. The devices show stable white light emission with Commission Internationale de L'Eclairage color coordinates (0.3511, 0.3437), and the white light intensity keeps unchanged after continuously working for 16 hours. The results indicate that CsPbX3@SiO2 quantum dots can be an ideal down-conversion fluorescent material for white light-emitting diode devices.

scholarly journals Perovskite Light-Emitting Devices with Doped Hole Transporting Layer

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1670
Author(s):  
Zhiwei Peng ◽  
Yuhan Gao ◽  
Guohua Xie
Keyword(s):  
Quantum Dots ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Control Device ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Improvement Factor ◽  
Hole Transporting ◽  
Perovskite Quantum Dots

Perovskite quantum dots (PQDs) have drawn global attention in recent years and have been used in a range of semiconductor devices, especially for light-emitting diodes (LEDs). However, because of the nature of low-conductive ligands of PQDs and surface and bulk defects in the devices, charge injection and transport should be carefully managed in order to maximize the electroluminescent performances. In this study, we employed three p-dopants, i.e., 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), 1,3,4,5,7,8-hexafluoro-11,11,12,12-tetracyanonaphtho-2,6-quinodimethane (F6-TCNNQ), and 11,11,12,12-tetracyanonaphtho-2,6-quinodimethane (TCNH14), respectively doped into the commonly used hole transporting layer (HTL) poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA). Compared with the devices with the neat PTAA, those with the doped PTAA as the HTLs achieved the improved electroluminescent performances. In particular, the device with the strong oxidant F4-TCNQ exhibited an improvement factor of 27% in the peak external quantum efficiency compared with the control device with the neat PTAA. The capacitance and transient electroluminescent measurements were carried out to identify the imperceptible interactions in the doped HTL and at the interface between the HTL and PQDs.

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