ABSTRACT Mechanoluminescence, defined as the non‐thermal emission of light in response to mechanical stimulation, has garnered significant attention over the past two decades, with research predominantly centered on enhancing the emission intensity of active phosphors. Nevertheless, in all‐inorganic mechanoluminescent systems, emission modulation has remained largely confined to adjusting the applied mechanical load to attain a desired output intensity. Here, we report tunable and persistent light emission in glass and partially crystallized glass ceramics derived from the ZnO–B 2 O 3 –GeO 2 chemical system. Through designing a coordination mismatch for the luminescent center (Mn 2+ ) in the amorphous and crystalline phases, two markedly distinct luminescence responses (red and green emissions, respectively) are achieved. Subsequently, by employing a simple, remote, and non‐optical excitation via ultrasound, charge carriers trapped within the crystalline phase preferentially recombine radiatively, enabling reversible switching of the persistent luminescence color. This double‐phase glass ceramic approach provides a novel pathway for integrating the durability of inorganic phosphors with enhanced tunability, thereby advancing the development of stimuli‐responsive composites for prospective applications such as smart lighting, display technologies, bioimaging, optical thermometry, and information encryption.
Yang et al. (2026) studied this question.