scholarly journals Ligand & band gap engineering: tailoring the protocol synthesis for achieving high-quality CsPbI3 quantum dots

Nanoscale ◽  
2020 ◽  
Vol 12 (26) ◽  
pp. 14194-14203 ◽  
Author(s):  
Ehsan Hassanabadi ◽  
Masoud Latifi ◽  
Andrés. F. Gualdrón-Reyes ◽  
Sofia Masi ◽  
Seog Joon Yoon ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Band Gap ◽  
Optoelectronic Devices ◽  
High Quality ◽  
Band Gap Engineering ◽  
Hot Injection ◽  
Perovskite Quantum Dots

Hot-injection has become the most widespread method used for the synthesis of perovskite quantum dots (QDs) with enormous interest for application in 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).

Control of Ordering-Disordering Defect Parameters for the Realization of Efficient Opto-Electronic Devices

1992 ◽  
Vol 262 ◽  
Author(s):  
J. P. André ◽  
P. Bellon
Keyword(s):  
Band Gap ◽  
Growth Parameters ◽  
Growth Models ◽  
Electronic Devices ◽  
Optoelectronic Devices ◽  
Band Gap Energy ◽  
Laser Application ◽  
High Quality ◽  
Band Gap Engineering ◽  
Gap Energy

ABSTRACTEpitaxial growth of III/V compounds with tight band gap engineering is essential for the realization of efficient optoelectronic devices. Using MOVPE, high quality materials have been grown with anomalous low band gap energy. The order/disorder phenomena and their relation to the band gap energy in the GalnP/AlGalnP system are reported. The effect of the growth parameters on the ordered phase and the band gap Eg will be presented by using TEM and PL characterizations. The growth models will be discussed. The importance of the ordering phenomena will be illustrated by short wavelength laser application, the emission wavelength being as low as 650 ran at 300 K. And a possible future laser structure will be proposed.

scholarly journals Red Light-Emitting Diodes with All-Inorganic CsPbI3/TOPO Composite Nanowires Color Conversion Films

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Lung-Chien Chen ◽  
Yi-Tsung Chang ◽  
Ching-Ho Tien ◽  
Yu-Chun Yeh ◽  
Zong-Liang Tseng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Light Emitting Diode ◽  
Red Light ◽  
Trioctylphosphine Oxide ◽  
Optical And Electrical Properties ◽  
Colloidal Solutions ◽  
High Quality ◽  
Light Emitting ◽  
Hot Injection ◽  
Color Conversion

AbstractThis work presents a method for obtaining a color-converted red light source through a combination of a blue GaN light-emitting diode and a red fluorescent color conversion film of a perovskite CsPbI3/TOPO composite. High-quality CsPbI3 quantum dots (QDs) were prepared using the hot-injection method. The colloidal QD solutions were mixed with different ratios of trioctylphosphine oxide (TOPO) to form nanowires. The color conversion films prepared by the mixed ultraviolet resin and colloidal solutions were coated on blue LEDs. The optical and electrical properties of the devices were measured and analyzed at an injection current of 50 mA; it was observed that the strongest red light intensity was 93.1 cd/m2 and the external quantum efficiency was 5.7% at a wavelength of approximately 708 nm when CsPbI3/TOPO was 1:0.35.

Growth of CdSSe quantum dots in borosilicate glass by controlled heat treatment for band gap engineering

2018 ◽  
Vol 86 ◽  
pp. 424-432 ◽  
Author(s):  
S.R. Munishwar ◽  
P.P. Pawar ◽  
S.Y. Janbandhu ◽  
R.S. Gedam
Keyword(s):  
Heat Treatment ◽  
Quantum Dots ◽  
Band Gap ◽  
Borosilicate Glass ◽  
Band Gap Engineering

scholarly journals Quantum Dots and Applications

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 897
Author(s):  
Chang-Yeol Han ◽  
Hyun-Sik Kim ◽  
Heesun Yang
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Band Gap ◽  
Light Emitting Diodes ◽  
Photovoltaic Cells ◽  
Core Shell ◽  
Special Issue ◽  
High Quality ◽  
Light Emitting ◽  
Size Dependent

It is the unique size-dependent band gap of quantum dots (QDs) that makes them so special in various applications. They have attracted great interest, especially in optoelectronic fields such as light emitting diodes and photovoltaic cells, because their photoluminescent characteristics can be significantly improved via optimization of the processes by which they are synthesized. Control of their core/shell heterostructures is especially important and advantageous. However, a few challenges remain to be overcome before QD-based devices can completely replace current optoelectronic technology. This Special Issue provides detailed guides for synthesis of high-quality QDs and their applications. In terms of fabricating devices, tailoring optical properties of QDs and engineering defects in QD-related interfaces for higher performance remain important issues to be addressed.

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.

An Improved Strategy for High-Quality Cesium Bismuth Bromine Perovskite Quantum Dots with Remarkable Electrochemiluminescence Activities

2019 ◽  
Vol 91 (13) ◽  
pp. 8607-8614 ◽  
Author(s):  
Yue Cao ◽  
Ziyi Zhang ◽  
Lingling Li ◽  
Jian-Rong Zhang ◽  
Jun-Jie Zhu
Keyword(s):  
Quantum Dots ◽  
High Quality ◽  
Perovskite Quantum Dots

Atom Probe Tomography of Compound Semiconductors for Photovoltaic and Light-Emitting Device Applications

2012 ◽  
Vol 20 (3) ◽  
pp. 18-24 ◽  
Author(s):  
Pyuck-Pa Choi ◽  
Oana Cojocaru-Mirédin ◽  
Daniel Abou-Ras ◽  
Raquel Caballero ◽  
Dierk Raabe ◽  
...  
Keyword(s):  
Band Gap ◽  
Optoelectronic Devices ◽  
Compound Semiconductors ◽  
Atom Probe ◽  
Energy Band Gap ◽  
Band Gap Engineering ◽  
Light Emitting ◽  
Direct Energy ◽  
Device Applications ◽  
High Absorption

Compound semiconductors belong to the most important materials for optoelectronic applications. Many of them exhibit favorable optical properties, such as a direct energy band gap (in contrast to silicon) and high-absorption coefficients over a wide spectral range. Moreover, varying the composition of the compound or substituting some of its elements often allows for controlled band gap engineering and optimization for specific applications. Because many compound semiconductors enable efficient conversion of light into electricity and vice versa, they are commonly used materials for optoelectronic devices.

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