Self-organized Ge1−xSnxquantum dots formed on insulators and their room temperature photoluminescence

In this study, we examined the self-organized formation of Ge1−xSnxquantum dots (QDs) on insulators based on a simple sputtering process and considered their luminescence properties. First, we systematically discussed the control factors in the self-organized formation of Ge1−xSnxQDs; the introduced Sn content and the deposition temperature should be related to the surface-migration of Sn atoms. Under sufficiently controlled conditions, we achieved the self-organized formation of Ge1−xSnxQDs surrounded by amorphous-like shells with a dot size of 9.3 nm, Sn content of 19% ± 10%, and dot density of 1.5 × 1011 cm−2and they showed a 2.0 μm photoluminescence peak at RT. Furthermore, the formation of multilayered Ge1−xSnxQDs structures was demonstrated, and they exhibited excellent thermal stability up to 400 °C while maintaining a dot-like morphology without causing the agglomeration. Therefore, the self-organized formation of Ge1−xSnxQDs is useful for realizing light-emitting devices for optical interconnects.