+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Photoluminescence from quasi-type-II spherical CdSe-CdS core-shell quantum dots

Photoluminescence from quasi-type-II spherical CdSe-CdS core-shell quantum dots

Applied Optics 52(1): 105-109

Spherical CdSe-CdS core-shell quantum dots (QDs) are found to be flexible in the transition between the type-I regime and the type-II regime with different core/shell dimensions. The quasi-type-II feature of the colloidal dots is confirmed with time-resolved photoluminescence (PL) measurements. Two recombination paths of the excitons with significantly different decay rates are observed and analyzed. The spherical CdSe-CdS core-shell QDs are numerically simulated to investigate the carrier separation. A relatively long radiative lifetime and high degree of spatial carrier separation provide good potential to achieve lasing under continuous-wave excitation. Amplified spontaneous emission at room temperature is detected from the QDs embedded in the polymer matrix. It is shown that a larger shell thickness results in a lower pumping threshold, while a smaller shell thickness leads to higher PL efficiency.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 054985504

Download citation: RISBibTeXText

PMID: 23292381

DOI: 10.1364/ao.52.000105

Related references

Enhancing the photoluminescence of polymer-stabilized CdSe/CdS/ZnS core/shell/shell and CdSe/ZnS core/shell quantum dots in water through a chemical-activation approach. Langmuir 25(19): 11732-11740, 2009

Synthesis of tetrahedral quasi-type-II CdSe-CdS core-shell quantum dots. Nanotechnology 22(42): 425202, 2011

Nearly suppressed photoluminescence blinking of small-sized, blue-green-orange-red emitting single CdSe-based core/gradient alloy shell/shell quantum dots: correlation between truncation time and photoluminescence quantum yield. Physical Chemistry Chemical Physics 20(15): 10332-10344, 2018

Synthesis of type-II CdSe(S)/Fe2O3core/shell quantum dots: the effect of shell on the properties of core/shell quantum dots. Journal of Materials Science 51(11): 5252-5258, 2016

Impact of Shell Thickness on Photoluminescence and Optical Activity in Chiral CdSe/CdS Core/Shell Quantum Dots. Acs Nano 11(9): 9207-9214, 2017

Type-II quantum dots: CdTe/CdSe(core/shell) and CdSe/ZnTe(core/shell) heterostructures. Journal of the American Chemical Society 125(38): 11466, 2003

Super sensitization: grand charge (hole/electron) separation in ATC dye sensitized CdSe, CdSe/ZnS type-I, and CdSe/CdTe type-II core-shell quantum dots. Chemistry 20(41): 13305-13313, 2014

Effect of hole transporting materials on photoluminescence of CdSe core/shell quantum dots. Guang Pu Xue Yu Guang Pu Fen Xi 29(12): 3204-3207, 2009

Photoluminescence of CdSe/ZnS core-shell quantum dots stabilized in water with a pseudopeptidic gemini surfactant. Nanoscale 3(9): 3613-3615, 2011

Hybrid Colloidal Stabilization Mechanism toward Improved Photoluminescence and Stability of CdSe/CdS Core/Shell Quantum Dots. Langmuir 33(28): 7124-7129, 2017

Effect of protein molecules on the photoluminescence properties and stability of water-soluble CdSe/ZnS core-shell quantum dots. Chinese Science Bulletin 58(21): 2616-2621, 2013

Controlling charge separation and recombination rates in CdSe/ZnS type I core-shell quantum dots by shell thicknesses. Journal of the American Chemical Society 132(42): 15038-15045, 2010

Sensing of ozone based on its quenching effect on the photoluminescence of CdSe-based core-shell quantum dots. Microchimica Acta 183(11): 3019-3024, 2016

Type-II CdSe/CdTe/ZnTe (core-shell-shell) quantum dots with cascade band edges: the separation of electron (at CdSe) and hole (at ZnTe) by the CdTe layer. Small 1(12): 1215-1220, 2005

The use of heat transfer fluids in the synthesis of high-quality CdSe quantum dots, core/shell quantum dots, and quantum rods. Nanotechnology 16(10): 2000-2011, 2005