Optical and Electrical Properties of CdTe Nanocrystal Quantum Dots Passivated in Amorphous TiO2 Thin Film Matrix

1998 ◽  
Vol 536 ◽  
Author(s):  
A. C. Rastogi ◽  
S. N. Sharma ◽  
Sandeep Kohli
Keyword(s):  
Thin Film ◽  
Quantum Dots ◽  
Volume Fraction ◽  
Electrical Coupling ◽  
Theoretical Models ◽  
Nanocrystal Size ◽  
Quantum Size ◽  
Cdte Nanocrystal ◽  
Nanocrystal Quantum Dots ◽  
Amorphous Tio2

AbstractCdTe nanocrystal quantum dots sequestered in TiO2 thin film matrix have been synthesized by r.f. sputtering from a composite CdTe/TiO2 target. CdTe nanocrystal formation is nucleation controlled as their size (11-25 nm), dispersion and volume fraction (0.065-0.2) increases with film thickness, substrate temperature (100°C) and thermal treatment. The optical band gap derived from the onset of absorption coefficient showed blue shifts concurrent with the CdTe nanocrystal size reduction due to quantum size effects. These shifts, not consistent with theoretical models based on strong or weak confinement regimes, are explained on the basis of anisotropic growth and formation of CdTe nanocrystal clusters. TiO2, in addition to being an ideal passivator and providing a barrier for carrier confinement to observe quantum effects, shows O2 vacancy dependent conductivity modulation. Electrical conductivity variation with CdTe nanocrystal size and density is attributed to electrical coupling and tunneling behavior of carriers between CdTe nanocrystallites.

Optical Properties of CdTe Nanocrystal Quantum Dots, Grown in the Presence of Cd0Nanoparticles

2007 ◽  
Vol 111 (29) ◽  
pp. 10841-10847 ◽  
Author(s):  
Ruth Osovsky ◽  
Viki Kloper ◽  
Joanna Kolny-Olesiak ◽  
Aldona Sashchiuk ◽  
Efrat Lifshitz
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Cdte Nanocrystal ◽  
Nanocrystal Quantum Dots

scholarly journals Exciton lifetimes of CdTe nanocrystal quantum dots in high magnetic fields

2011 ◽  
Vol 83 (3) ◽  
Author(s):  
J. H. Blokland ◽  
V. I. Claessen ◽  
F. J. P. Wijnen ◽  
E. Groeneveld ◽  
C. de Mello Donegá ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Magnetic Fields ◽  
High Magnetic Fields ◽  
Cdte Nanocrystal ◽  
Nanocrystal Quantum Dots

Thin Amorphous TiO2 Shell on CdSe Nanocrystal Quantum Dots Enhances Photocatalysis of Hydrogen Evolution from Water

2014 ◽  
Vol 118 (41) ◽  
pp. 23627-23634 ◽  
Author(s):  
Sooho Lee ◽  
Kangha Lee ◽  
Whi Dong Kim ◽  
Seokwon Lee ◽  
Do Joong Shin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Hydrogen Evolution ◽  
Nanocrystal Quantum Dots ◽  
Amorphous Tio2 ◽  
Tio2 Shell

The relaxation of compressive biaxial strains in SOS via microtwins

1989 ◽  
Vol 47 ◽  
pp. 608-609
Author(s):  
M. E. Twigg ◽  
E. D. Richmond ◽  
J. G. Pellegrino
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Molecular Beam Epitaxy ◽  
Compressive Stress ◽  
Vapor Deposition ◽  
Partial Dislocation ◽  
Molecular Beam ◽  
Volume Fraction ◽  
Chemical Vapor ◽  
Silicon Thin Film

For heteroepitaxial systems, such as silicon on sapphire (SOS), microtwins occur in significant numbers and are thought to contribute to strain relief in the silicon thin film. The size of this contribution can be assessed from TEM measurements, of the differential volume fraction of microtwins, dV/dν (the derivative of the microtwin volume V with respect to the film volume ν), for SOS grown by both chemical vapor deposition (CVD) and molecular beam epitaxy (MBE).In a (001) silicon thin film subjected to compressive stress along the [100] axis , this stress can be relieved by four twinning systems: a/6[211]/( lll), a/6(21l]/(l1l), a/6[21l] /( l1l), and a/6(2ll)/(1ll).3 For the a/6[211]/(1ll) system, the glide of a single a/6[2ll] twinning partial dislocation draws the two halves of the crystal, separated by the microtwin, closer together by a/3.

Tannin-based thin-film composite membranes integrated with nitrogen-doped graphene quantum dots for butanol dehydration through pervaporation

2021 ◽  
Vol 623 ◽  
pp. 119077
Author(s):  
Rumwald Leo G. Lecaros ◽  
Reincess E. Valbuena ◽  
Lemmuel L. Tayo ◽  
Wei-Song Hung ◽  
Chien-Chieh Hu ◽  
...  
Keyword(s):  
Thin Film ◽  
Quantum Dots ◽  
Graphene Quantum Dots ◽  
Composite Membranes ◽  
Film Composite ◽  
Nitrogen Doped ◽  
Thin Film Composite ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Organic-inorganic hybrid thin film light-emitting devices: interfacial engineering and device physics

2021 ◽  
Author(s):  
Chunxiu Zang ◽  
Mengxin Xu ◽  
Letian Zhang ◽  
Shihao Liu ◽  
Wenfa Xie
Keyword(s):  
Thin Film ◽  
Quantum Dots ◽  
Sandwich Structure ◽  
Device Physics ◽  
Hybrid Thin Film ◽  
Inorganic Hybrid ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Interfacial Engineering ◽  
Organic Light

Thin film light-emitting devices (LEDs) with sandwich structure, such as organic light emitting devices (OLEDs), quantum dots LEDs (QLEDs) and perovskite LEDs (PeLEDs), have attracted wide attentions because of their...

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.

The Emission Property of Phosphors LEDs Based on ZnCuInS/ZnSe/ZnS Quantum Dots

2014 ◽  
Vol 989-994 ◽  
pp. 623-625
Author(s):  
Ke Bi ◽  
Wen Yan Liu ◽  
Tian Yue Xu ◽  
Tie Qiang Zhang ◽  
Yu Zhang
Keyword(s):  
Quantum Dots ◽  
Photoluminescence Spectrum ◽  
Stokes Shift ◽  
Core Shell ◽  
Photoluminescence Properties ◽  
Red Emission ◽  
Light Emitting ◽  
Quantum Size ◽  
Gan Led ◽  
Photoluminescence Peak

.In this research, ZnCuInS/ZnSe/ZnS quantum dots (QDs) have been studied as an excellent red emitting source for blue GaN LED because of its non-toxic deep red emmission, and large Stokes shift properties. In the paper ZnCuInS/ZnSe/ZnS core/shell quantum dots were prepared with the particle size of 4.5nm. According to the measurement of photoluminescence spectrum emitted by ZnCuInS/ZnSe/ZnS core/shell quantum dots, the emitting peak of 700 nm and the full was achieved as red emitter.It was found that absorption edge and photoluminescence peak shifted to shorter wavelength with decreasing the nanocrystal size due to quantum size effect.Meanwhile, we were prepared ZnCuInS/ZnSe/ZnS core/shell quantum dot light emitting diodes and their photoluminescence properties were studied. After the suitable bias was applied on the films, increasing the ZnCuInS/ZnSe/ZnS QDs concentration in the blue GaN chips, red emission increased with decreasing LED’s blue light.

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