Carrier decay process of nanoscaled SiGe particles embedded in SiO2 matrix

Nanoscaled SiGe particles (NPs) are formed by ions implantation and annealing treatment methods. For any sample, the total dose of Si and Ge dopants is 3×10¹⁶ cm^-2. Strong photoluminescence (PL) peaks centered around red emission region are observed. This PL peak red shifts from 653 nm-695 nm with the increase of Ge-doping dose, which is ascribed to the quantum confinement effect. The PL lifetime spectra exhibit a stretched exponential decay with characteristic decay time τ varying from 50.2-23.1 μs and dispersion factor β in the range of 0.67-0.86.