ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Quantum Dots (QDs) of CdSxSe1-x embedded in borosilicate glass matrix (BGM) havebeen grown using colored glass filter (RG695). Double-Step (DS) annealing method was adopted inwhich nucleation is achieved at a lower temperature (475ºC) without any crystallization. To obtaincrystallization on these nucleation centers, the annealing temperature is raised to 575ºC at which thenucleation rate is negligible. QDs of various average radii and volume fractions are grown byvarying the annealing duration from 3 to 11hrs. QDs corresponding to higher annealing duration arefound to have low size dispersion (SD) and high volume fraction but weak quantum confinement,while, the QDs corresponding to lower annealing durations have high quantum confinement due totheir much lower radii as compare to Bohr exciton radius, their SD is high and volume fraction low.For nonlinear optical applications the SD must be low and volume fraction should be high. Attempthas been made to optimize the two parameters. Further it has been concluded that there is nocontribution of the band edge recombination to the PL and the origin of the PL is due to shallowtraps existing in the volume of the QDs. Studies of absorption and PL have also been made on thesamples aged for 18, 24 and 36 months. It is found that the effect of aging is to increase theabsorption coefficient, reduce the shallow trap centers and reduce the SD
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.31.161.pdf
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