Enhancing the adjustable range of saturation in color reflectors using a phase-change material as an effective absorption base

Structural color technology has garnered extensive attention in the development of ink-free color technology for applications such as color displays, color reflectors, and colorimetric devices. A Fabry-Perot (F-P) structure formed by stacking a metal base, an interference cavity, and a phase change material layer (MIP) is of significant interest as a lithography-free and scalable color-reflecting structure. Such a structure can selectively reflect interfered light over a range of visible wavelengths, resulting in bright colors. However, obtaining a wide range of saturation regulation spaces has become a challenge. In this study, an F-P color reflector based on a phase-change material (PCM) base is proposed, which consists of a PCM base, an interference layer, and a PCM top layer (PIP). The results of the finite element simulation and experimental measurements demonstrated that the PIP reflector had an adjustable saturation range 10.75 times larger than that of the MIP reflector. The effects of the structure size and phase change of the PCM layer on the structural characteristics were further analyzed. In addition, the performance of laser-induced color change and its application in color printing were demonstrated. The present study sheds new light on color reflectors, and the strategy proposed indicates their potential optoelectronic applications based on saturation modulation.