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Detailed Program
Paper Number : GL-O07
Time Frame : 14:07~14:19
Presentation Date : Thurse day, 27, November
Session Name : Glass & Optp-Electonic Materials
Session Chair 1# : Woon Jin Chung
Session Chair 2# : Hirokazu Masai
Luminescence and Absorption Properties of PbS Quantum Dots in Glasses
Won Ji Park
POSTECH
It is important to control the size of quantum dots (QDs) precisely because QDs have unique optical and electronic properties depending on their sizes. Previously, it was necessary to carefully control the heat-treatment temperature and duration if one were to design the optical properties of quantum dots size precipitated in glasses. We have investigated the influence of rare-earth ions on the control of nucleation and growth of the semiconductor nanocrystals in silicate glasses.
Glasses containing different concentration of Nd3+ ions were prepared through conventional melt-quenching methods, PbS quantum dots (QDs) were precipitated in glasses by heat treatment method. The peak positions of the absorption from PbS QDs moved to short-wavelength side as the concentration of Nd3+ ions in glass increased under the same heat-treatment condition. For example, center wavelengths of the absorption bands decreased from 1398 nm for a Nd3+-free glass to 1272 nm at Nd2O3 content of 0.6 mol %.(Fig. 1(a)) The center wavelengths of the PL spectra also moved from 1518 nm to 1370 nm as the concentration of Nd3+ ions increased.(Fig. 1(b)) It was proposed that Er3+ ions act as the nucleation centers for the formation of PbS QDs in glasses.[1-2] In this work, absorption, photoluminescence and TEM analysis were performed to understand of the role of rare-earth ions. Lifetimes of several rare-earths energy levels were measured and extended x-ray absorption fine structure (EXAFS) investigation were also performed to analyse the local environment of rare-earth ions.



[Fig. 1.] Normalized (a) absorption and (b) PL spectra of the glasses with different Nd2O3 concentrations heat-treated at 500oC for 25h.

References:

[1] S. M. Shim, C. Liu, Y. K. Kwon, J. Heo, J. Am. Ceram. Soc., 93 (2010) 3092-3094
[2] M. A. Kim, Y. K. Kwon, C. Liu, J. Heo, J. Non-Cryst. Solids, 383 (2014) 173-175
Acknowledgements :