Fig. 1. Schematic of designed color device consisting of Al/Sb2S3/SiO2 stacking layers deposited onto substrate. The focused nanosecond laser with long and low-intensity pulse is utilized to print the color image (crystallization of Sb2S3) while a picosecond laser with short and high-intensity pulse is used to erase the image (amorphization of Sb2S3).

Fig. 2. (a) Optical images of Sb2S3 films with different SiO2 thicknesses and Sb2S3 thickness of 50 nm, where panels (i) to (v) denote the SiO2 thicknesses of 0, 10, 20, 30, and 40 nm, respectively. The optical images are captured under the same illumination conditions and lens magnification. Scale bar: 100 μm. (b) Thickness reduction of Sb2S3 films dependent on SiO2 thickness with Sb2S3 thicknesses of d=20  nm, 50 nm, and 100 nm, respectively; inset, schematic of thin film structures; the crystallization of Sb2S3 is realized at annealing temperature of 350°C for 20 min. (c) XRD patterns of crystalline Sb2S3 thin films with/without SiO2 layer, where the thicknesses of Sb2S3 and SiO2 are 50 nm and 20 nm, respectively.

Fig. 3. (a) Optical constants of Al, SiO2, as-deposited (aSb2S3) and crystalline Sb2S3 (cSb2S3) films. (b) Experimental and simulated reflectance spectra at aSb2S3 thicknesses of 24, 119, and 133 nm; right inset, corresponding color plates. Scale bar: 30 μm. (c) Color coordinates from the simulated spectra plotted in CIE (International Commission on Illumination) 1931 chromaticity diagram, where white pentagons and blue dots represent aSb2S3 and cSb2S3, respectively. (d), (e) Simulated color pallets of Al/Sb2S3/SiO2-stacking layer at various Sb2S3 thicknesses and phase change process. (f) CIE 1931 diagram at various SiO2 thicknesses.

Fig. 4. (a) Calculated color contrast for various thicknesses of Sb2S3. (b) Multilevel color plates via thermal annealing processes at different temperatures. Scale bar: 150 μm. (c) Corresponding reflectance spectra. (d) XRD patterns of color device, where the annealing time is 5 min.

Fig. 5. Color images printing by pattern mask-deposition method. (a)–(c) Green images of bird, butterfly, and eagle via fixing aSb2S3 thickness at 130 nm. (d)–(f) Different color images at aSb2S3 thicknesses of 18 nm, 118 nm, and 105 nm, respectively. (g)–(i) Color images at as-deposited state, 245°C and 250°C annealing, respectively, where the Sb2S3 thickness is 24 nm. Scale bar: 2 cm.

Fig. 6. Flexible color printing. (a) Reflectance spectra measured after bending 10 times, and color images printed onto PI substrate with 100 nm Al/125 nm aSb2S3/20  nmSiO2-stacking layer (insets, i, ii, and iii are the images before, during, and after bending 10 times, respectively). Scale bar: 2 cm. (b) Reflectance spectra at different incident angles.

Fig. 7. (a) Optical photographs of color device with 25-nm-thick Sb2S3. Scale bar: 50 μm. (b) Corresponding reflectance spectra. (c) Raman spectra of device. For (a)–(c), (I) as-deposited film, (II) thermal crystallization, (III) reamorphization—first, picosecond laser to switch the crystalline region back to the amorphous state, (IV) laser crystallization, nanosecond laser to recrystallize the amorphous region, (V) reamorphization—second, picosecond laser to erase the crystalline region again. (d) Reflectance spectra during 10-time reversible cycles and (e) reversible cyclability of devices.

Fig. 8. (a) Optical micrographs of rewritable color flowers printed onto 25-nm-thick Sb2S3-based devices. Scale bar: 50 μm. (b) Multilevel color flowers printed onto the device at different powers; the images are erased by picosecond laser-induced amorphization. Scale bar: 20 μm. (c) Dot arrays patterns printed onto the device, all of which are patterned with a laser power of 6 mW and pulse width of 10 ns. Scale bar: 5 μm.

Fig. 9. Thermal field distribution of high-resolution pixel dot: (a) thickness direction, (b) radial direction, and (c) corresponding temperature profile.