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Volume 6
Research & Reviews: Journal of Material Sciences
ISSN: 2321-6212
Materials Physics 2018
August 16-17, 2018
August 16-17, 2018 | London, UK
4
th
International Conference on
Condensed Matter and Materials Physics
Inhibit source of 1.3 um quantum dot intermixing using STO for high laser performance
H Hashim, A Mohd
and
A B Ooi
King Abdullah University for Science and Technology, KSA
S
ignificant behavior has been observed by studying the PL emission for post growth thermal annealing in a long wavelength
QDs materials, capped with STO, highly recommended as inhibit source for intermixing, and a promising materials for
highly laser performance. For intermixing studies, samples were deposited with Strontium titanium oxide (STO) 100 nm
thickness using pulsed layer deposition (PLD), annealing used rapid thermal annealing (RTP) under GaAs overpressure at
temperature ranging 650 to 725°C for 2 minutes were applied on it to cause thermal interdiffusion with a different rate. Samples
were excited by 1064 nm laser source, and PL spectrum under 77 K were measured for all different annealing samples. Figure
1 shows a clear inhibition diffusion behavior when intermixing until 725°C annealed temperature, this gives a good reason
for recommendation of this material in multiple wavelength chip, when using a mask with it, and SiO
2
as a second promote
intermixing source. A strain effect clear in the deposited samples shows as a red shift in the spectra. A second observation have
been seen is the merging of the two peaks, GS and first excited state, while annealing the diffusion of In in the dots cause a
change in the QDs density of state, which seen as a merging in the two states, in order to estimate the critical temperature that
the states have been merged, we plot the different in energy between GS, ES1 as a function of annealing temperatures- figure
2, the point where the linear line intercept with X axis represent the critical temperature. Gaussian fitting have been used to
estimate the peaks wavelength for all spectrum, figure (3) shows the behaviors when annealing, for whole spectrum a decrease
in FWHM has been observed while annealing until 700°C around critical temperature it started to increase (because of third
peak effect), For GS behavior, it started to decrease with annealing (because of merging with ES1, above TC, it completely
merge so couldn't be estimated from Gaussian fitting. For ES1: it started to increase, (cause of GS merge with it), then at TC
started to decrease (because of appearance of third peak).
Hala.alhashim@kaust.edu.sa.
Res. Rev. J Mat. Sci. 2018, Volume 6
DOI: 10.4172/2321-6212-C2-018