scholarly journals Enhanced Air Stability of Perovskite Quantum Dots by Manganese Passivation

Technologies ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Ryota Sato ◽  
Kazuki Umemoto ◽  
Satoshi Asakura ◽  
Akito Masuhara
Keyword(s):  
Quantum Dots ◽  
Thermal Conditions ◽  
The Other ◽  
Quantum Yields ◽  
Full Width ◽  
Half Maximum ◽  
Air Humidity ◽  
Passivating Layer ◽  
Perovskite Quantum Dots ◽  
Color Tunability

Organic-inorganic perovskite quantum dots (PeQDs) have attracted attention due to their excellent optical properties, e.g., high photoluminescence quantum yields (PLQYs; >70%), a narrow full width at half maximum (FWHM; 25 nm or less), and color tunability adjusted by the halide components in an entire tunability (from 450 nm to 730 nm). On the other hand, PeQD stability against air, humidity, and thermal conditions has still not been enough, which disturbs their application. To overcome these issues, with just a focus on the air stability, Mn2+ ion passivated perovskite quantum dots (Mn/MAPbBr3 QDs) were prepared. Mn2+ could be expected to contract the passivating layer against the air condition because the Mn2+ ion was changed to the oxidized Mn on PeQDs under the air conditions. In this research, Mn/MAPbBr3 QDs were successfully prepared by ligand-assisted reprecipitation (LARP) methods. Surprisingly, Mn/MAPbBr3 QD films showed more than double PLQY stability over 4 months compared with pure MAPbBr3 ones against the air, which suggested that oxidized Mn worked as a passivating layer. Improving the PeQD stability is significantly critical for their application.

Promoting photoluminescence quantum yields of glass-stabilized CsPbX3 (X = Cl, Br, I) perovskite quantum dots through fluorine doping

Nanoscale ◽  
2019 ◽  
Vol 11 (37) ◽  
pp. 17216-17221 ◽  
Author(s):  
Daqin Chen ◽  
Yue Liu ◽  
Changbin Yang ◽  
Jiasong Zhong ◽  
Su Zhou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Yields ◽  
Fluorine Doping ◽  
Glass Crystallization ◽  
Perovskite Quantum Dots

Highly luminescent glass-stabilized CsPbX3 (X = Cl, Br, I) perovskite QDs are fabricated via an in situ glass crystallization strategy and fluorine doping.

Room-temperature and gram-scale synthesis of CsPbX3 (X = Cl, Br, I) perovskite nanocrystals with 50–85% photoluminescence quantum yields

2016 ◽  
Vol 52 (45) ◽  
pp. 7265-7268 ◽  
Author(s):  
Song Wei ◽  
Yanchun Yang ◽  
Xiaojiao Kang ◽  
Lan Wang ◽  
Lijian Huang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Quantum Yields ◽  
Perovskite Nanocrystals ◽  
Perovskite Quantum Dots

CsPbX3 perovskite quantum dots with 50–85% photoluminescence quantum yields have been successfully synthesized at room temperature in open air.

High Resolution X-Ray Diffraction Analysis of Piezoelectric LiNbO3 Films.

1995 ◽  
Vol 401 ◽  
Author(s):  
Yoshihiko Shibata ◽  
Naohiro Kuze ◽  
Masahiro Matsui ◽  
Masaki Kanal ◽  
Tomoji Kawai
Keyword(s):  
Laser Ablation ◽  
High Resolution ◽  
The Other ◽  
Full Width ◽  
Half Maximum ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Excimer Laser Ablation ◽  
Sapphire Substrates

AbstractThin LINbO3 films are deposited on (001) sapphire and (001) LiTaO3 substrates by using pulsed excimer-laser ablation. These films are evaluated by high-resolution X-ray diffraction (HRXRD) analysis. Strained LiNbO3 films in which the a-axis is longer and the c-axis is shorter than those of LiNbO3 single crystals are deposited on the sapphire substrates. On the other hand, extremely high-quality LiNbO3 films in which the a-axis of the films is the same as that of substrates are grown on the LiTaO substrates. X-ray rocking curves for the (006) reflection showed very narrow full width at half maximum (FWHM) of 208 arcsec for the films on the sapphire substrates, and 9 arcsec for the films on LiTaO3 substrates.

Instrumental Discrepancy and Relation of Stress Condition between ESD Association and JEDEC Standards on ESD CDM Test

2009 ◽  
Author(s):  
Yuparwadee Satirakul ◽  
Tanawat Butngam ◽  
Surapol Phunyapinuant
Keyword(s):  
Stress Level ◽  
Discharge Current ◽  
Linear Relation ◽  
Stress Condition ◽  
The Other ◽  
Full Width ◽  
Half Maximum ◽  
Electrical Failure ◽  
Package Size ◽  
The Relationship

Abstract Instrumental difference including characteristic aspects between ESDA and JEDEC standards on CDM test have been investigated and discussed. ESDA test systems provides higher discharge current, lower rise time and lower full width at half maximum at the same stress level, which is due to the higher inductance in the discharge path. We have succeeded in finding out the linear relation of the stress condition between these 2 standards. Furthermore, the current monotonically increases with the stress level for all capacitances and depends on the package size as expected. The relationship between current and package area is proportional because a larger package affords a higher capacitance. The current tends to saturate with a package size over 250 mm2 in both standards. The electrical failure yield of each standard system can be predicted by a stress condition of the other. The stress condition in JEDEC standard is undoubtedly a subset of the ESDA standard.

THE GRADIENT OF THE BARRIERS AFFECTS THE RESONANT ENERGY

2003 ◽  
Vol 17 (09) ◽  
pp. 383-386 ◽  
Author(s):  
MASATO OHMUKAI
Keyword(s):  
Transmission Coefficient ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
The Other ◽  
Numerical Calculations ◽  
Full Width ◽  
Half Maximum ◽  
Double Barrier ◽  
Resonant Energy

Double barrier structures with a gradient have been studied by numerical calculations of transmission coefficient following a transfer matrix method. As the slope of the barriers becomes steep, the resonant energy is lowered. On the other hand, the full width at half maximum does not depend on the gradient.

In Situ X-Ray Stress Measurement in Electrodeposited Cu Foils under Tensile and Fatigue Loading

2007 ◽  
Vol 353-358 ◽  
pp. 2395-2398 ◽  
Author(s):  
Yoshiaki Akiniwa ◽  
Tsuyoshi Suzuki ◽  
K. Tanaka
Keyword(s):  
Plastic Deformation ◽  
Deformation Behavior ◽  
Stress Measurement ◽  
Fatigue Loading ◽  
The Other ◽  
Full Width ◽  
Half Maximum ◽  
X Ray ◽  
The Difference

Monotonic and cyclic loadings were subjected to electrodeposited copper foils (thickness is 8 and 20 μm), and the deformation behavior was observed. In-situ X-ray stress measurement was carried out under monotonic loading. The tensile strength of 8 μm foil was higher than that of 20 μm foil. On the other hand, the elongation of 8 μm foil was smaller. When the plastic deformation occurred, difference between the X-ray stress and the applied stress became large. The difference of 20 μm foil was larger than that of 8 μm foil. Fatigue strength of 8 μm foil was also higher than that of 20 μm foil. The value of the full width at half maximum, FWHM, increased dramatically at the first cycle, and then the value became nearly constant. Just before fracture, the value increased again. The change in FWHM corresponded to the change in the accumulated ratchet strain.

scholarly journals Synthetic and Post-Synthetic Strategies to Improve Photoluminescence Quantum Yields in Perovskite Quantum Dots

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 957
Author(s):  
ChaeHyun Lee ◽  
Soo Jeong Lee ◽  
YeJi Shin ◽  
Yeonsu Woo ◽  
Sung-Hwan Han ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Raw Materials ◽  
Photophysical Properties ◽  
Optoelectronic Devices ◽  
Charge Recombination ◽  
Quantum Yields ◽  
Recrystallization Process ◽  
Recombination Processes ◽  
Perovskite Quantum Dots ◽  
Efficient Charge

Making high-quality raw materials is the key to open the versatile potential of next generation materials. All-inorganic CsPbX3 (X: Cl−, Br−, and/or I−) perovskite quantum dots (PQDs) have been applied in various optoelectronic devices, such as photocatalysis, hydrogen evolution, solar cells, and light-emitting diodes, due to their outstanding photophysical properties, such as high photoluminescence quantum yield (PLQY), absorption cross-section, efficient charge separation, and so on. Specifically, for further improvement of the PLQY of the PQDs, it is essential to diminish the non-radiative charge recombination processes. In this work, we approached two ways to control the non-radiative charge recombination processes through synthetic and post-synthetic processes. Firstly, we proposed how refinement of the conventional recrystallization process for PbI2 contributes to higher PLQY of the PQDs. Secondly, after halide exchange from CsPbI3 PQDs to CsPbBr3, through an in situ spectroelectrochemical setup, we monitored the positive correlation between bromide deposition of on the surface of the perovskite and photoluminescence improvement of the CsPbBr3 perovskite film through electrodeposition. These two strategies could provide a way to enhance the photophysical properties of the perovskites for application to various perovskite-based optoelectronic devices.

Stable CsPbBr3 perovskite quantum dots with high fluorescence quantum yields

2018 ◽  
Vol 42 (12) ◽  
pp. 9496-9500 ◽  
Author(s):  
Min Zhang ◽  
Zhi-Quan Tian ◽  
Dong-Liang Zhu ◽  
He He ◽  
San-Wei Guo ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Perovskite Quantum Dots ◽  
High Fluorescence ◽  
The Stability

After replacing oleylamine with (3-aminopropyl)triethoxysilane, the stability of the as-prepared CsPbBr3 QDs was significantly improved.

scholarly journals Correlation of near-unity quantum yields with photogenerated excitons in X-type ligand passivated CsPbBr3 perovskite quantum dots

2019 ◽  
Vol 1 (8) ◽  
pp. 2828-2834 ◽  
Author(s):  
Sunjoong Park ◽  
Hyunjin Cho ◽  
Wonseok Choi ◽  
Hanfeng Zou ◽  
Duk Young Jeon
Keyword(s):  
Quantum Dots ◽  
Radiative Decay ◽  
Quantum Yields ◽  
Nonradiative Decay ◽  
Perovskite Quantum Dots

The TCSPC analysis revealed that DDT-PQDs mainly performed single radiative decay, whereas PQDs showed additional slow nonradiative decay with rise of temperature.

Sign in / Sign up

Export Citation Format

Share Document