The Study Of Various Dynamic Display Optical Coatings Based On Phase-change Materials

Dynamic phase-change optical coating display technology is a new reflective color display which combines multilayer optical coating structure and phase-change materials.The dynamic color switching of this coating is realized by the optical property difference between different phase states of the phase change material?PCM?,it makes the phase-change optical coating breaks through the shortcomings of the traditional optical coating with invariable color.The phase-change optical coating display has many advantages including non-volatile,extremely fast refresh rate,etc.At present,the research on the phase-change optical coating display is still in its early stage.The reported research are basically based on GST,and are mostly focused on using multilayered phase-change layers to realize more colors modulation.And there are top-ITO layer upon GST layer to isolate the air.There is no research on the top-ITO layer in the structure and systematic study of the color rendering ability of the phase-change structure.This article found that changing the thickness of the top-ITO can effectively change the color of the phase-change coatings.which proves that the top-ITO layer plays an important role in the interference effect of the whole coating structure.This is a new discovery and the previous literatures never reported,and it has also corrected the biased conclusion in the previous literatures.And we propose a new modulation method based on the thickness of top-ITO layer and the bottom-ITO,the triangle gamut area of IGIP structure is increased by 205%after using this method.For studying the simpler structure,two kinds of phase-change display structures based on single ITO layer are designed,which are ITO/GST/Pt?IGP?structure and GST/ITO/Pt?GIP?structure.The three color modulation and color gamut range of this two structures are simulated and studied.For obtaining nontoxic optical coating with better color-modulation capability,a new phase-change display technology based on VO₂ is proposed and the ITO/VO₂/ITO/Pt?IVIP?display structure is designed.The color appearance of IVIP structure at 20?,68?and 100? is simulated,it shows that the single IVIP structure can achieve at least three colors switching.It is found that the thickness of the VO₂ layer between 75nm and 125nm can ensure the IVIP structure has better dynamic color change capability.