| AVS 59th Annual International Symposium and Exhibition | |
| Nanometer-scale Science and Technology | Monday Sessions |
| Session NS-MoM |
| Session: | Nanoparticles and Quantum Structures |
| Presenter: | A. Hernández-Hernández, CINVESTAV-IPN, Mexico |
| Authors: | A. Hernández-Hernández, CINVESTAV-IPN, Mexico F. De Moure-Flores, CINVESTAV-IPN, Mexico J.G. Quiñones-Galván, CINVESTAV-IPN, Mexico L.A. Hernández-Hernández, ESFM-IPN, Mexico J. Santoyo-Salazar, CINVESTAV-IPN, Mexico M. Meléndez-Lira, CINVESTAV-IPN, Mexico |
| Correspondent: | Click to Email |
As-grown light emitting self-assembled Ge nanocrystals (Ge-NCs) embedded in a SiO2 matrix were produced by a sequential deposition process of SiO2/Ge/SiO2 layers employing reactive radio frequency sputtering technique. Obtained Ge-NCs shown a crystallographic phase whose proportion, size, quality and specific orientation are determined by the oxygen partial pressure. Photoluminescence (PL) spectra indicate that the size distribution of Ge-NCs is reduced and centered at around 8 nm when higher oxygen partial pressure is employed; the formation of Ge-NCs is corroborated by transmission electron microscopy (TEM) measurements, their sizes are consistent with estimates from PL measurements. After vacuum annealing it is observed the elimination of an instable high pressure tetragonal phase of germanium present in as-grown samples. It is possible that this phase is related to the SiO2 matrix stress on the Ge-NCs. In addition, the PL peaks shifted to higher energies indicating the formation of Ge-NCs probably from Ge dispersed within SiO2 matrix. It was also found that the PL intensity increases drastically after annealing process. The strong size dependence of the PL spectra indicates that the observed PL originates from the recombination of electron-hole pairs confined in Ge-NCs.
† : partially funded by CONACyT-Mexico and ICYT-DF.