Efficient blue luminescence from colloidal CdSe quantum-dot quantum-well nanocrystals

2013 ◽  
Vol 1548 ◽  
Author(s):  
Y. Lu ◽  
X. A. Cao
Keyword(s):  
Quantum Dot ◽  
Quantum Well ◽  
Interface State ◽  
Full Width ◽  
Half Maximum ◽  
Light Emitting ◽  
Cladding Layer ◽  
Layer Adsorption ◽  
Cdse Quantum Dot ◽  
Outer Cladding

ABSTRACTCdS/CdSe/ZnS quantum dot quantum well (QDQW) nanocrystals were synthesized using the successive ion layer adsorption and reaction technique. CdSe QWs with a well width of 1.05 nm emitted blue light at 467 nm with a spectral full-width-at-half-maximum of ∼30 nm. It was found that a 3-monolayer ZnS outer cladding layer can effectively passivate the QDQW structures, leading to a ∼35% quantum yield (QY) of the QW photoluminescence. QDQW light-emitting diodes (LEDs) with blue QW electroluminescence (EL) were fabricated. The devices with an emitting layer comprising QDQWs embedded in a poly(N-vinylcarbazole) host were five times brighter than LEDs based on closely-packed QDQWs. However, the overall EL of the devices was dominated by interface state emission due to poor charge injection into the QDQWs.

Ultrabroad-band, red sufficient, solid white emission from carbon quantum dot aggregation for single component warm white light emitting diodes with a 91 high color rendering index

2019 ◽  
Vol 55 (46) ◽  
pp. 6531-6534 ◽  
Author(s):  
Ting Meng ◽  
Ting Yuan ◽  
Xiaohong Li ◽  
Yunchao Li ◽  
Louzhen Fan ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Full Width ◽  
Half Maximum ◽  
Light Emitting ◽  
White Emission ◽  
Carbon Quantum Dot ◽  
Warm White Light ◽  
Color Rendering Index ◽  
White Light Emitting Diodes ◽  
Color Rendering

An ultrabroad-band solid white emission from carbon quantum dot aggregation with a full width at half maximum over 200 nm throughout the entire visible light window and, even better, with a sufficient red component is first reported.

Efficient CdSe Quantum Dot-Sensitized Solar Cells Prepared by an Improved Successive Ionic Layer Adsorption and Reaction Process

Nano Letters ◽  
2009 ◽  
Vol 9 (12) ◽  
pp. 4221-4227 ◽  
Author(s):  
HyoJoong Lee ◽  
Mingkui Wang ◽  
Peter Chen ◽  
Daniel R. Gamelin ◽  
Shaik M. Zakeeruddin ◽  
...  
Keyword(s):  
Solar Cells ◽  
Quantum Dot ◽  
Reaction Process ◽  
Layer Adsorption ◽  
Cdse Quantum Dot ◽  
Sensitized Solar Cells ◽  
Ionic Layer

scholarly journals Performance Study of CdS/Co-Doped-CdSe Quantum Dot Sensitized Solar Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xiaoping Zou ◽  
Sheng He ◽  
Gongqing Teng ◽  
Chuan Zhao
Keyword(s):  
Solar Cells ◽  
Quantum Dot ◽  
Performance Study ◽  
Co Doping ◽  
Transfer Path ◽  
Layer Adsorption ◽  
Cdse Quantum Dot ◽  
Cascade Energy ◽  
Sensitized Solar Cells ◽  
Co Doped

In order to optimize the charge transfer path in quantum dot sensitized solar cells (QDSCs), we employed successive ionic layer adsorption and reaction method to dope CdSe with Co for fabricating CdS/Co-doped-CdSe QDSCs constructed with CdS/Co-doped-CdSe deposited on mesoscopic TiO2film as photoanode, Pt counter electrode, and sulfide/polysulfide electrolyte. After Co doping, the bandgap of CdSe quantum dot decreases, and the conduction band and valence band all improve, forming a cascade energy level which is more conducive to charge transport inside the solar cell and reducing the recombination of electron-hole thus improving the photocurrent and ultimately improving the power conversion efficiency. This work has not been found in the literature.

Hybrid CdSe-ZnS Quantum Dot-InGaN-GaN Quantum Well Red Light-Emitting Diodes

2008 ◽  
Vol 29 (7) ◽  
pp. 711-713 ◽  
Author(s):  
Chun-Yuan Huang ◽  
Yan-Kuin Su ◽  
Ying-Chih Chen ◽  
Ping-Chieh Tsai ◽  
Cheng-Tien Wan ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Quantum Well ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Light Emitting

scholarly journals Fabrication, Characterization, and Optimization of CdS and CdSe Quantum Dot-Sensitized Solar Cells with Quantum Dots Prepared by Successive Ionic Layer Adsorption and Reaction

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
H. K. Jun ◽  
M. A. Careem ◽  
A. K. Arof
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
Solar Cell Performance ◽  
Optimum Performance ◽  
Layer Adsorption ◽  
Cdse Quantum Dot ◽  
Sensitized Solar Cells ◽  
Ionic Layer ◽  
Dipping Time

CdS and CdSe quantum dot-sensitized solar cells (QDSSCs) were used for the study of determining the optimum preparation parameters that could yield the best solar cell performance. The quantum dots (QDs) were coated on the surface of mesoporous TiO2layer deposited on FTO substrate using the successive ionic layer adsorption and reaction (SILAR) method. In this method the QDs are allowed to grow on TiO2by dipping the TiO2electrode successively in two different solutions for predetermined times. This method allows the fabrication of QDs in a facile way. Three preparation parameters that control the QD fabrication were investigated: concentration of precursor solutions, number of dipping cycles (SILAR cycles), and dipping time in each solution. CdS based QDSSC showed optimum performance when the QDs were prepared from precursor solutions having the concentration of 0.10 M using 4 dipping cycles with the dipping time of 5 minutes in each solution. For CdSe QDSSC, the optimum performance was achieved with QDs prepared from 0.03 M precursor solutions using 7 dipping cycles with 30 s dipping time in each solution. The QDs deposited on TiO2surface were characterized using UV-vis absorption spectroscopy, FESEM, and TEM imaging.

InGaN/AlGaN Double-Heterostructure Blue Leds

1994 ◽  
Vol 339 ◽  
Author(s):  
Shuji Nakamura
Keyword(s):  
Blue Light ◽  
Full Width ◽  
Half Maximum ◽  
Ingan Layer ◽  
Peak Wavelength ◽  
Forward Voltage ◽  
High Brightness ◽  
Light Emitting ◽  
Double Heterostructure ◽  
First Time

ABSTRACTHigh-brightness InGaN/AlGaN double-heterostructure (DH) blue-light-emitting diodes (LEDs) with a luminous intensity of 1.2 cd were fabricated successfully for the first time. As an active layer, a Zn-doped InGaN layer was used. The peak wavelength and the full width at half-maximum of the electroluminescence were 450 nm and 70 nm, respectively. The forward voltage was as low as 3.6V at 20 mA.

Theoretical and Experimental Studies on Microcavity Organic Light-Emitting Diodes with Different Emitters

2015 ◽  
Vol 645-646 ◽  
pp. 1087-1092 ◽  
Author(s):  
Cui Yun Peng ◽  
Meng Jie Wei ◽  
Rong Juan Huang ◽  
Kun Ping Guo ◽  
Yue Lin Jing ◽  
...  
Keyword(s):  
Emission Intensity ◽  
Light Emitting Diodes ◽  
Experimental Studies ◽  
Experimental Results ◽  
Organic Light Emitting Diodes ◽  
Full Width ◽  
Half Maximum ◽  
Light Emitting ◽  
Organic Light ◽  
Electroluminescence Intensity

We have theoretically and experimentally investigated the microcavity organic light-emitting diodes (MOLEDs) that enhanced the emission intensity and narrowed the spectra simultaneously. In this work, MOLEDs with the reflectivities of 70% and 90% have been successfully fabricated. Comparing to non-cavity OLEDs, the maximum forward electroluminescence intensity and the peak luminescence can be improved by 6.8 times and 2.2 times, respectively. The full width at half maximum could be sharply narrowed to 10 nm. The different configurations of MOLEDs with varied emitting layers have also been evaluated which fitted well with the experimental results.

Core-shell structure and quantum effect of CdSe/HgSe/CdSe quantum dot quantum well

2001 ◽  
Vol 29 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Ling Xu ◽  
Kunji Chen ◽  
Jianming Zhu ◽  
Hongming Chen ◽  
Hongbin Huang ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Quantum Well ◽  
Shell Structure ◽  
Quantum Effect ◽  
Core Shell ◽  
Cdse Quantum Dot ◽  
Core Shell Structure
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