Growth and characterization of Si1−x Getx QDs on Si/Si0.8Ge0.2 layer

Abstract

Si1−x Getx QDs structures were grown onto Si/Si0.8Ge0.2 layer using RPCVD system. Ge composition in Si1−x Getx QDs was determined as about 30% and 40%. Three peaks are observed in Raman spectrum, which are located at about 520, 410, and 295 cm−1, corresponding to the vibration of Si-Si, Si-Ge, and Ge-Ge phonons, respectively, and the Si1−x Getx QDs related peak was located at 490 cm−1. The PL spectrum that originates from the radiative recombinations came from the Si substrate, the Si0.8Ge0.2 layer and Si1−x Getx QDs. For Si1−x Getx QDs, the transition peaks related to the QDs region observed in the photocurrent spectrum were preliminarily assigned to electron-heavy hole (e-hh) and electron-light hole (e-lh) fundamental excitonic transitions.