scholarly journals Improving Photoluminescence Quantum Yield of CdTe Quantum Dots Using a Binary Solvent (Water + Glycerin) in the One-Pot Approach Synthesis

Author(s):  
Lucas da Rosa ◽  
Isabella Aversa ◽  
Ellen Raphael ◽  
André Polo ◽  
Alfredo Duarte ◽  
...  

The present work describes the comparison of the optical and structural properties between CdTe quantum dots (QD) synthesized in water and in the binary solvent (water + glycerin) via one-pot approach synthesis. The optical properties of the nanocrystals obtained with different synthesis parameters were characterized by UV-visible and photoluminescence spectroscopies. The structural chracterization were performed by Fourier transform infrared spectroscopy (FTIR), zeta potential, size-distribution by dynamic light scattering (DLS), X-ray diffraction (XRD), and also by high-resolution transmission electron microscopy (HRTEM). The optical properties of CdTe QD when synthesized in the binary solvent were better, resulting in the increase of photoluminescence quantum yield (φƒ). The CdTe QD prepared in 120 min, at pH 10.0, in the Cd:Te molar ratio 20:1, using the molar ratio 1:1.5 of Cd:TGA (thioglycolic acid), exhibited a narrow photoluminescence band and enhanced φƒ for the samples synthesized in a binary solvent in comparison to water solvent (58.4 and 49.5%, respectively).

Nanoscale ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 2484-2491 ◽  
Author(s):  
Yue Zhai ◽  
Xue Bai ◽  
Gencai Pan ◽  
Jinyang Zhu ◽  
He Shao ◽  
...  

Co-doping of cation (La3+) and anion (F−) ions is a feasible method to improve the optical properties of CsPbCl3 QDs, and high photoluminescence quantum yield of 36.5% is achieved in CsPb(Cl0.7F0.3)3:La3+ QDs.


2017 ◽  
Vol 8 ◽  
pp. 1156-1166 ◽  
Author(s):  
Pavel Aleksandrovich Kotin ◽  
Sergey Sergeevich Bubenov ◽  
Natalia Evgenievna Mordvinova ◽  
Sergey Gennadievich Dorofeev

We report the synthesis of colloidal CdSe quantum dots doped with a novel Ag precursor: AgCl. The addition of AgCl causes dramatic changes in the morphology of synthesized nanocrystals from spherical nanoparticles to tetrapods and finally to large ellipsoidal nanoparticles. Ellipsoidal nanoparticles possess an intensive near-IR photoluminescence ranging up to 0.9 eV (ca. 1400 nm). In this article, we explain the reasons for the formation of the ellipsoidal nanoparticles as well as the peculiarities of the process. The structure, Ag content, and optical properties of quantum dots are also investigated. The optimal conditions for maximizing both the reaction yield and IR photoluminescence quantum yield are found.


RSC Advances ◽  
2014 ◽  
Vol 4 (68) ◽  
pp. 36024-36030 ◽  
Author(s):  
J. C. L. Sousa ◽  
M. G. Vivas ◽  
J. L. Ferrari ◽  
C. R. Mendonca ◽  
M. A. Schiavon

In the present study, we report the synthesis of glutathione (GSH) capped CdTe quantum dots (QDs) using the one-pot approach as well as their optical properties.


2021 ◽  
Author(s):  
Byeong M. Oh ◽  
Yong-Cheol Joung ◽  
Jian Zheng ◽  
Na Young Cho ◽  
Myungkwan Song ◽  
...  

Perovskite quantum dots (PeQDs) have a high-photoluminescence quantum yield with high color purity, which meets the latest requirements of the display industry. However, the difficulty in patterning of PeQDs limits...


2011 ◽  
Vol 306-307 ◽  
pp. 1262-1265 ◽  
Author(s):  
Zhi Min Yuan ◽  
Jie Yang ◽  
Yu Lan Zhang ◽  
Rui Li Zhang ◽  
Ning Liu ◽  
...  

An environmentally friendly synthesis was developed to fabricate aqueous CdTe quantum dots (QDs) using thilglycolic acid (TGA) as a capping agent. Optimal preparation conditions including pH (11.2) and TGA/Cd molar ratio (1.5:1) resulted in CdTe QDs with high photoluminescence (PL) quantum yield up to 56%. The TGA-capped CdTe QDs exhibited tunable PL from green to red. Lifetime measurement indicated that the average lifetime of the TGA-capped QDs increased with increasing their sizes (27.5 and 37.2 ns for the QDs with PL peak wavelength of 607 and 636 nm, respectively). The PL of the QDs revealed the dependence of temperature, in which the QDs exhibited a red-shifted PL peak with increasing temperature. Such PL behavior depended strongly on the QD sizes.


2021 ◽  
Vol 9 (5) ◽  
pp. 1555-1566
Author(s):  
Andrés F. Gualdrón-Reyes ◽  
David F. Macias-Pinilla ◽  
Sofia Masi ◽  
Carlos Echeverría-Arrondo ◽  
Said Agouram ◽  
...  

The Pb substitution in quantum dots (PQDs) with lesser toxic metals has been widely searched to be environmentally friendly, and be of comparable or improved performance compared to the lead-perovskite.


Author(s):  
Lin Yang ◽  
Bowen Fu ◽  
Xu Li ◽  
Hao Chen ◽  
Lili Li

All inorganic perovskite quantum dots (QDs) have received great attention owing to their excellent performance in optoelectronic applications. However, they often suffer from the defect-related photoluminescence (PL) quenching and phase...


Nanoscale ◽  
2021 ◽  
Author(s):  
Dongdong Yan ◽  
Qionghua Mo ◽  
Shuangyi Zhao ◽  
Wensi Cai ◽  
Zhigang Zang

With a high photoluminescence quantum yield (PLQY) being able to exceed 90% for those prepared by hot injection method, CsPbBr3 quantum dots (QDs) have attracted intensive attentions for white light-emitting...


2021 ◽  
Author(s):  
Wenbing Cao ◽  
Yuhan Wu ◽  
Xin Li ◽  
Xuanfeng Jiang ◽  
Yuhong Zhang ◽  
...  

Abstract Silane-functionalized carbon dots (SiCDs) can be exploited as effective color converting materials for the solid-state light-emitting devices. However, most of SiCDs reported thus far have shown photoluminescence emissions in the blue and green spectral range, which limit them to construct an efficient white light-emitting diodes (WLEDs) due to the lack of long-wavelength emission. Herein, a series of double silane-functionalized carbon dots (DSiCDs) were prepared via a one-step solvothermal method. The results show that the organic functional group of the silane has great influence on the optical properties of DSiCDs and the number of alkoxy group in the silane has great influence on coating properties of DSiCDs. In addition, the DSiCDs prepared by (3-aminopropyl)triethoxysilane and N-[3-(Trimethoxysilyl)propyl]ethylenediamine with molar ratio of 7:3 show excellent optical properties with the maximum emission at 608 nm under 400 nm excitation. Furthermore, they can be completely dried within 1 h at room temperature to form fluorescent coating with high stability and strong adhesion to the substrate. Together with their excellent optical and coating properties, they can be directly coated on LED chips to prepare WLEDs, with a CIE coordinate of (0.33,0.31), color rendering index of 81.6, and color temperature of 5774 K.


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