Synthesis of Light Emitting Ge Nanocrystals by Reactive RF Sputtering
| Periodical | Solid State Phenomena (Volumes 178 - 179) |
|---|---|
| Main Theme | Gettering and Defect Engineering in Semiconductor Technology XIV |
| Edited by | W. Jantsch and F. Schäffler |
| Pages | 61-66 |
| DOI | 10.4028/www.scientific.net/SSP.178-179.61 |
| Citation | Arturo Hernandez-Hernandez et al., 2011, Solid State Phenomena, 178-179, 61 |
| Online since | August, 2011 |
| Authors | Arturo Hernandez-Hernandez, Victor Tapio Rangel-Kuoppa, Thomas Plach, Francisco De Moure-Flores, Jose G. Quiñones-Galvan, Karen E. Nieto Zepeda, Martin Zapata-Torres, Miguel Meléndez-Lira |
| Keywords | Efros-Shkovskii Hopping, Ge Nanocrystals, Light Emitting, Reactive RF Sputtering |
| Price | US$ 28,- |
In this work we report the results of the synthesis, structural and optical characterization of SiO2/Ge/SiO2 heterostructures by reactive RF sputtering. The SiO2 films were grown by reactive sputtering employing a plasma mixture of oxygen and argon. The Ge layer was grown employing an Ar atmosphere. The samples were prepared on p-type Si (1 1 1) substrates by reactive sputtering. The effect of the partial pressure of oxygen on the electronic properties of the heterostructure is reported[1]. Structural characterization was carried out by grazing angle X-ray difraction. Surface roughness was quantified by atomic force microscopy. The presence of Ge nanocrystals (Ge-NCs) was evidenced by X-ray diffraction. The vibrational properties were studied by Raman spectroscopy. The Raman spectra showed modes associated to germanium indicating the formation of low dimensionality germanium particles embedded within a SiO2 matrix. Photoluminescence emission is observed around ~1.7 eV and it is associated to the quantum confinement of carriers in Ge-NCs. Ohmic contacts were deposited using a van der Pauw geometry employing an a AuSb alloy for the contacts. Temperature dependent Hall (T-Hall) measurements were done between 35 K and 150 K, using the van der Pauw method. The results indicated low resistivity values that could be explained due to some variable range hopping conduction mechanism.
