A Modified Chalcogenide Flux Method for Confining Metal Halide Nanocrystals into Transparent Glassy Matrix

Controlled nanocrystallization of glasses is prerequisite for developing transparent glass-ceramics with functionalities that determined by precipitated nanocrystals and residual glassy matrix. However, simultaneously control of nanocrystal phase and size in glasses has not yet been achieved. Herein, we introduce a modified chalcogenide flux protocol to precisely design metal halide (MX) nanocrystals in glassy matrices. The size amount variation of MX nanocrystals were quantified with thorough microscopic analysis, demonstrating growth of MX nanocrystals occurs with the depletion of smaller ones. We reveal an Ostwald-ripening controlled nanocrystallization mechanism for simultaneously controlling over the crystal phases and crystal growth of precipitates in chalcogenide glassy matrices. These results not only show a new fact for understanding the nature of glass formation and crystallization, but also provide a simple and convenient route to robust glass-ceramic materials embedded with a variety of MX nanocrystals for novel photonic applications.