Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

Simple fabrication processes of Ge-based nanostructures in glasses are very interesting due to the highly tuneable electronic structure and many relevant applications. We address the recent advances in the production of regularly ordered Ge/Si and Ge/metal core/shell nanostructures formed by magnetron sputtering deposition in glass alumina matrix [1]. The regular ordering of these nanostructures is achieved by the self-ordering growth regime that occurs under specific deposition conditions [2]. We have developed the theory and software for the analysis of such materials by small grazing incidence angle x ray scattering (GISAXS) [3].
The light absorption properties of these films are significantly different compared to films that form quantum dot lattices of the pure Ge, Si, metal or a solid solution of the constituents. The Ge/Si core/shell quantum dots show a strong narrow absorption peak that characterizes a type II confinement in accordance with the theoretical predictions. In addition, we show that the peak position and width depend strongly on the size of Ge core and Si shell [4]. These materials are very interesting for the application in quantum dot solar cells.
[1] M. Buljan, et al., Nanotechnology 26 065602 (2015).
[2] M. Buljan, et al., J. Appl. Cryst. 46, 1490-1500 (2013).
[3] M. Buljan, et al., Acta Cryst. A, 68, 124 (2012); http://homer.zpr.fer.hr/gisaxstudio/doku.php
[4] N. Nekic, et al., (in preparation)