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.

scholarly journals Ultrasensitive and ultrathin phototransistors and photonic synapses using perovskite quantum dots grown from graphene lattice

2020 ◽  
Vol 6 (7) ◽  
pp. eaay5225 ◽  
Author(s):  
Basudev Pradhan ◽  
Sonali Das ◽  
Jinxin Li ◽  
Farzana Chowdhury ◽  
Jayesh Cherusseri ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optoelectronic Devices ◽  
Generation Efficiency ◽  
Charge Generation ◽  
Graphene Lattice ◽  
New Directions ◽  
Perovskite Quantum Dots ◽  
Efficient Charge ◽  
Halide Perovskite ◽  
Optoelectronic Applications

Organic-inorganic halide perovskite quantum dots (PQDs) constitute an attractive class of materials for many optoelectronic applications. However, their charge transport properties are inferior to materials like graphene. On the other hand, the charge generation efficiency of graphene is too low to be used in many optoelectronic applications. Here, we demonstrate the development of ultrathin phototransistors and photonic synapses using a graphene-PQD (G-PQD) superstructure prepared by growing PQDs directly from a graphene lattice. We show that the G-PQDs superstructure synchronizes efficient charge generation and transport on a single platform. G-PQD phototransistors exhibit excellent responsivity of 1.4 × 108 AW–1 and specific detectivity of 4.72 × 1015 Jones at 430 nm. Moreover, the light-assisted memory effect of these superstructures enables photonic synaptic behavior, where neuromorphic computing is demonstrated by facial recognition with the assistance of machine learning. We anticipate that the G-PQD superstructures will bolster new directions in the development of highly efficient optoelectronic devices.

scholarly journals Encapsulated Passivation of Perovskite Quantum Dot (CsPbBr3) Using a Hot-Melt Adhesive (EVA-TPR) for Enhanced Optical Stability and Efficiency

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 419
Author(s):  
Saradh Prasad ◽  
Mamduh J. Aljaafreh ◽  
Mohamad S. AlSalhi ◽  
Abeer Alshammari
Keyword(s):  
Quantum Dots ◽  
Band Gap ◽  
Surface Defects ◽  
Optoelectronic Devices ◽  
Ethylene Vinyl Acetate ◽  
Light Emitting ◽  
Optical Stability ◽  
Perovskite Quantum Dots ◽  
Polymer Light Emitting Diodes ◽  
Hot Melt

The notable photophysical characteristics of perovskite quantum dots (PQDs) (CsPbBr3) are suitable for optoelectronic devices. However, the performance of PQDs is unstable because of their surface defects. One way to address the instability is to passivate PQDs using different organic (polymers, oligomers, and dendrimers) or inorganic (ZnS, PbS) materials. In this study, we performed steady-state spectroscopic investigations to measure the photoluminescence (PL), absorption (A), transmission (T), and reflectance (R) of perovskite quantum dots (CsPbBr3) and ethylene vinyl acetate/terpene phenol (1%) (EVA-TPR (1%), or EVA) copolymer/perovskite composites in thin films with a thickness of 352 ± 5 nm. EVA is highly transparent because of its large band gap; furthermore, it is inexpensive and easy to process. However, the compatibility between PQDs and EVA should be established; therefore, a series of analyses was performed to compute parameters, such as the band gap, the coefficients of absorbance and extinction, the index of refractivity, and the dielectric constant (real and imaginary parts), from the data obtained from the above investigation. Finally, the optical conductivities of the films were studied. All these analyses showed that the EVA/PQDs were more efficient and stable both physically and optically. Hence, EVA/PQDs could become copolymer/perovskite active materials suitable for optoelectronic devices, such as solar cells and perovskite/polymer light-emitting diodes (PPLEDs).

scholarly journals Flexible and efficient perovskite quantum dot solar cells via hybrid interfacial architecture

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Long Hu ◽  
Qian Zhao ◽  
Shujuan Huang ◽  
Jianghui Zheng ◽  
Xinwei Guan ◽  
...  
Keyword(s):  
Thin Film ◽  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
High Performance ◽  
Mechanical Stability ◽  
Mechanical Adhesion ◽  
Perovskite Quantum Dots ◽  
Efficient Charge ◽  
Photovoltaic Technologies

AbstractAll-inorganic CsPbI3 perovskite quantum dots have received substantial research interest for photovoltaic applications because of higher efficiency compared to solar cells using other quantum dots materials and the various exciting properties that perovskites have to offer. These quantum dot devices also exhibit good mechanical stability amongst various thin-film photovoltaic technologies. We demonstrate higher mechanical endurance of quantum dot films compared to bulk thin film and highlight the importance of further research on high-performance and flexible optoelectronic devices using nanoscale grains as an advantage. Specifically, we develop a hybrid interfacial architecture consisting of CsPbI3 quantum dot/PCBM heterojunction, enabling an energy cascade for efficient charge transfer and mechanical adhesion. The champion CsPbI3 quantum dot solar cell has an efficiency of 15.1% (stabilized power output of 14.61%), which is among the highest report to date. Building on this strategy, we further demonstrate a highest efficiency of 12.3% in flexible quantum dot photovoltaics.

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.

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 Photophysical Properties of Multilayer Graphene–Quantum Dots Hybrid Structures

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 714 ◽  
Author(s):  
Ivan Reznik ◽  
Andrey Zlatov ◽  
Mikhail Baranov ◽  
Roman Zakoldaev ◽  
Andrey Veniaminov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Energy Transfer ◽  
Average Rate ◽  
Photophysical Properties ◽  
Graphene Quantum Dots ◽  
Hybrid Structures ◽  
Multilayer Graphene ◽  
Cdse Qds ◽  
Efficient Charge ◽  
Photoinduced Processes

Photoelectrical and photoluminescent properties of multilayer graphene (MLG)–quantum dots (QD) hybrid structures have been studied. It has been shown that the average rate of transfer from QDs to the MLG can be estimated via photoinduced processes on the QDs’ surfaces. A monolayer of CdSe QDs can double the photoresponse amplitude of multilayer graphene, without influencing its characteristic photoresponse time. It has been found that efficient charge or energy transfer from QDs to MLG with a rate higher than 3 × 108 s−1 strongly inhibits photoinduced processes on the QD surfaces and provides photostability for QD-based structures.

Charge transfer dynamics in CsPbBr3 perovskite quantum dots–anthraquinone/fullerene (C60) hybrids

Nanoscale ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 862-869 ◽  
Author(s):  
Sadananda Mandal ◽  
Lijo George ◽  
Nikolai V. Tkachenko
Keyword(s):  
Quantum Dots ◽  
Charge Transfer ◽  
Organic Molecules ◽  
Photophysical Properties ◽  
Fullerene C60 ◽  
Colloidal Quantum Dots ◽  
Perovskite Quantum Dots ◽  
Charge Transfer Dynamics

An advantage of colloidal quantum dots, particularly perovskite quantum dots (PQDs), as photoactive components is that they easily form complexes with functional organic molecules, which results in hybrids with enriched photophysical properties.

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