SiGe/Ge Core-Multishell Nanocrystals Grown by Solid-State Dewetting and Ge Thermal Condensation for Photodetection and Solar cell Applications

Abstract

This study introduces a novel method for synthesizing SiGe/Ge core-multishell nanocrystals on insulating thin films for optoelectronic applications. The approach combines solid-state dewetting under ultra-high vacuum with Ge thermal condensation in SiGe layers, producing hemispherical nanocrystals with narrow size dispersion and well-defined crystallographic facets. Structural and spectroscopic analyses confirm high purity, uniform Ge composition, and complex core-shell architecture. Electrical characterizations validate successful integration into MIS structures, while photocurrent response under visible light highlights their potential for next-generation optoelectronic devices. This work offers a pathway for designing advanced functional nanostructures.