scholarly journals Enhanced photoresponse of ZnO quantum dot-decorated MoS2 thin films

RSC Advances ◽  
2017 ◽  
Vol 7 (27) ◽  
pp. 16890-16900 ◽  
Author(s):  
Ghazanfar Nazir ◽  
M. Farooq Khan ◽  
Imtisal Akhtar ◽  
Kamran Akbar ◽  
Praveen Gautam ◽  
...  
Keyword(s):  
Thin Films ◽  
Quantum Dots ◽  
Quantum Dot ◽  
Thin Layer ◽  
Zno Quantum Dots

This paper reports on high photo responsivity (Rλ ∼ 1913 AW−1) of MoS2 photodetector by decorating a thin layer of ZnO quantum dots on MoS2.

scholarly journals Effect of Growth Temperature on the Characteristics of CsPbI3-Quantum Dots Doped Perovskite Film

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4439
Author(s):  
Shui-Yang Lien ◽  
Yu-Hao Chen ◽  
Wen-Ray Chen ◽  
Chuan-Hsi Liu ◽  
Chien-Jung Huang
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Quantum Dots ◽  
Quantum Dot ◽  
Growth Temperature ◽  
Electron Mobility ◽  
Surface Defects ◽  
Different Temperatures ◽  
Pb Doping ◽  
Pristine Film

In this study, adding CsPbI3 quantum dots to organic perovskite methylamine lead triiodide (CH3NH3PbI3) to form a doped perovskite film filmed by different temperatures was found to effectively reduce the formation of unsaturated metal Pb. Doping a small amount of CsPbI3 quantum dots could enhance thermal stability and improve surface defects. The electron mobility of the doped film was 2.5 times higher than the pristine film. This was a major breakthrough for inorganic quantum dot doped organic perovskite thin films.

Deposition, Characterization, Performance of Cadmium Sulfide Quantum Dots Thin Films Using SILAR Technique for Quantum Dot Sensitized Solar Cell Applications

2020 ◽  
Vol 835 ◽  
pp. 374-383
Author(s):  
Zeinab Abdel Hamid ◽  
H.B. Hassan ◽  
Manal A. Hassan ◽  
M. Hussein Mourad ◽  
S. Anwar
Keyword(s):  
Thin Films ◽  
Quantum Dots ◽  
Particle Size ◽  
Quantum Dot ◽  
Cadmium Sulfide ◽  
Precursor Solution ◽  
Transparent Conductive Oxide ◽  
Spectra Analysis ◽  
Number Of Cycles ◽  
Silar Technique

This work deals with the deposited cadmium sulfide (CdS) quantum dots thin films on transparent conductive fluorine-doped tin oxide (FTO) substrates prepared by successive ionic layer adsorption and reaction technique (SILAR). QD deposition based on SILAR is easy, cheap and effective method which improves the surface quality and performance of QD-based devices. The effect of the number of cycles of SILAR on the morphology and size of the quantum dots has been investigated. SILAR technique was adopted for the deposition of CdS on anatase TiO2 and the three main factors contributing to the performance of QDs processed by SILAR, namely the number of cycles used, the concentration of the precursor solution, and the reaction dipping time, are discussed. The structural, morphological and optical properties were studied using X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Raman spectra analysis and UV-Vis NIR analysis, respectively. The particle size of CdS was calculated from XRD pattern using Debye Scherrer’s equation and the calculated particle size was 4.5-9.5 nm. Using CdSQDs, quantum dot sensitized solar cells (QDSSC) were fabricated on FTO substrates as being a transparent conductive oxide. Optical absorption property proved that the band gap energy value was about 2.44 eV. The result delivered from J-V curve revealed that the overall energy conversion efficiency increased with increasing the deposition cycles giving the best efficiency of 2.73 % at 7 cycles.

Enhanced photoelectrochemical conversion performance of ZnO quantum dots sensitized α-Fe 2 O 3 thin films

2015 ◽  
Vol 40 (16) ◽  
pp. 5583-5592 ◽  
Author(s):  
Ashi Ikram ◽  
Sonal Sahai ◽  
Snigdha Rai ◽  
Sahab Dass ◽  
Rohit Shrivastav ◽  
...  
Keyword(s):  
Thin Films ◽  
Quantum Dots ◽  
Zno Quantum Dots ◽  
Conversion Performance

Atomic Force Microscopy and Near-Field Scanning Optical Microscopy Study of Quantum-Dot Assemblies and Fractal Films

1999 ◽  
Vol 5 (S2) ◽  
pp. 968-969
Author(s):  
W. D. Bragg ◽  
K. Banerjee ◽  
M. J. Campin ◽  
Z. C. Ying ◽  
Jane G. Zhu ◽  
...  
Keyword(s):  
Thin Films ◽  
Quantum Dots ◽  
Atomic Force Microscopy ◽  
Quantum Dot ◽  
Optical Microscopy ◽  
Metal Salt ◽  
Fractal Structures ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scanning Optical Microscopy

Quantum dots and nanocrystalline films are interesting materials due to their novel properties, not achievable from the bulk materials [1]. New materials fabricated by assembling of quantum dots and nanostructured materials exhibit, for example, high optical nonlinearities. Fractal structures [2] can be formed from quantum-dot aggregates or films. Scanning probe microscopy is the essential technique to characterize these nanometer-scaled materials?Gold nanocluster colloids are synthesized in the interior of surfactant aggregates known as inverse micelles, without the use of water to solubilize the metal salt [3]. The size of the Au quantum dots is well controlled in the colloid synthesis and selected using chromatography. The Au clusters are then sprayed onto a glass slides to form thin films made of Au quantum dots. We have also used the laser ablation technique [4] to grow Ag nanoparticles, fractal aggregates and thin films. These samples have been studied using atomic force microscopy (AFM) and nearfield scanning optical microscopy.

scholarly journals ZnO quantum dots modified bioactive glass nanoparticles with pH-sensitive release of Zn ions, fluorescence, antibacterial and osteogenic properties

2016 ◽  
Vol 4 (48) ◽  
pp. 7936-7949 ◽  
Author(s):  
Kai Zheng ◽  
Miao Lu ◽  
Bogdan Rutkowski ◽  
Xinyi Dai ◽  
Yuyun Yang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Antibacterial Activity ◽  
Quantum Dot ◽  
Bioactive Glass ◽  
Ph Sensitive ◽  
Zno Quantum Dots ◽  
Zn Ions

Zn containing bioactive glass nanoparticles fabricated by ZnO quantum dot coating of BG nanoparticles exhibit apatite forming ability, antibacterial activity and non-cytotoxicity.

Towards full-colour tunable photoluminescence of monolayer MoS2/carbon quantum dot ultra-thin films

2017 ◽  
Vol 5 (25) ◽  
pp. 6352-6358 ◽  
Author(s):  
Weitao Su ◽  
Yuchan Wang ◽  
Weiwei Wu ◽  
Haiying Qin ◽  
Kaixin Song ◽  
...  
Keyword(s):  
Thin Films ◽  
Quantum Dots ◽  
Quantum Dot ◽  
Carbon Quantum Dots ◽  
Monolayer Mos2 ◽  
Carbon Quantum Dot

We prepared 1L-MoS2/CQD material using highly luminescent carbon quantum dots and monolayer MoS2; we achieved tunable luminescence from 400 to 700 nm.

Interpretation of the Phonon Frequency Shifts in ZnO Quantum Dots

2005 ◽  
Vol 872 ◽  
Author(s):  
Khan A. Alim ◽  
Vladimir A. Fonoberov ◽  
Alexander A. Balandin
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Phonon Frequency ◽  
Low Voltage ◽  
Red Shift ◽  
Phonon Confinement ◽  
Free Standing ◽  
Frequency Shifts ◽  
Zno Quantum Dots ◽  
Phonon Localization

AbstractNanostructures made of zinc oxide (ZnO), a wide-bandgap semiconductor, have recently attracted attention due to their proposed applications in low-voltage and short-wavelength (368 nm) electro-optical devices, transparent ultraviolet (UV) protection films, gas sensors, and varistors. Raman spectroscopy presents a powerful tool for identifying specific materials in complex structures and for extracting useful information on properties of nanoscale objects. At the same time the origin of Raman peak deviation from the bulk values is not always well understood for new material systems. There are three main mechanisms that can induce phonon shifts in the free-standing undoped ZnO nanostructures: (i) phonon confinement by the quantum dot boundaries; (ii) phonon localization on defects and (iii) the laser-induced heating in nanostructure ensembles. Here, we report results of the combined non-resonant and resonant Raman scattering studies of an ensemble of ZnO quantum dots with diameter 20 nm. Based on our experimental data, we have been able to identify the origin of the observed phonon frequency shifts. It has been found that the ultraviolet laser heating of the ensemble induces a large red shift of the phonon frequencies. It is calculated that the observed red shift of 14 cm-1 corresponds to the local temperature of the quantum dot ensemble of about 700°C.

scholarly journals Synthesis of Colloidal Mn2+: ZnO Quantum Dots and High-Tc Ferromagnetic Nanocrystalline Thin Films.

ChemInform ◽  
2004 ◽  
Vol 35 (42) ◽  
Author(s):  
Nick S. Norberg ◽  
Kevin R. Kittilstved ◽  
James E. Amonette ◽  
Ravi K. Kukkadapu ◽  
Dana A. Schwartz ◽  
...  
Keyword(s):  
Thin Films ◽  
Quantum Dots ◽  
High Tc ◽  
Zno Quantum Dots ◽  
Nanocrystalline Thin Films
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