Mid-infrared absorption in self-assembled Ge quantum dots grown on Si substrate

Publisher Website
Google Scholar
Abstract
Mid-infrared absorption in boron-doped and modulation boron- doped self-assembled Ge quantum dots grown on (001) oriented Si substrates is reported for the first time in this paper. The structures, which were grown by a solid source molecular beam epitaxy system, are composed of 20 or 30 periods of Ge dot layers and Si spacer films. The structural properties of the multilayers and some uncapped Ge dots on sample surface were tested by cross-sectional transmission electron and atomic force microscopes, respectively. Through use of Fourier transform infrared and Raman spectrometers, infrared absorption signals peaking in the mid-infrared range were observed. The absorption is strongly polarized along the growth axis of the samples. Experimental and theoretical analysis suggests that the mid-infrared response be attributed to intraband transitions in the valence band of the Ge quantum dots. This study demonstrates the application potential of these kinds of Ge/Si quantum dot multilayer structures for developing mid-infrared photodetectors.

This publication has 0 references indexed in Scilit: