Self-organized Ge_1−x Sn _x quantum dots formed on insulators and their room temperature photoluminescence

Abstract In this study, we examined the self-organized formation of Ge 1− x Sn x quantum 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 Ge 1− x Sn x QDs; 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 Ge 1− x Sn x QDs surrounded by amorphous-like shells with a dot size of 9.3 nm, Sn content of 19% ± 10%, and dot density of 1.5 × 10 11 cm −2 and they showed a 2.0 μ m photoluminescence peak at RT. Furthermore, the formation of multilayered Ge 1− x Sn x QDs 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 Ge 1− x Sn x QDs is useful for realizing light-emitting devices for optical interconnects.