Achieved RGBY Four Colors Changeable Electrochromic Pixel by Coelectrodeposition of Iron Hexacyanoferrate and Molybdate Hexacyanoferrate

Although multicolor electrochromic materials and devices have been studied by many researchers, there is still none an inorganic single-layer film that has red, blue, and green three typical color states, while red, green, and blue (RGB) are indispensably for multicolor display. Iron hexacyanoferrate (FeHCF) is a kind of well-studied inorganic electrochromic material with relatively colorful properties and a great family of analogues. In this Research Article, the RGBY film with red, green, blue and yellow four typical color states are obtained successfully by coelectrodeposition of FeHCF and molybdate hexacyanoferrate (MoOHCF). This film contains the electrochromic properties of both components. Moreover, benefiting from its high A+ (alkali cation ions that can insert/extract into/from the framework, such as Li+ and K+) content, the redox process of RGBY film can be fully completed to achieve rich color variation. The absorptivity adjustment range of RGBY film at 730 and 440 nm are 0.81 and 0.43, respectively. The response time of RGBY films varies from 3 to 30 s between states and maintains its optical properties without significant decay during 1000 cycles. Finally, a pixelated electrode and a facile electrochromic device based on RGBY film have been developed to exhibit its high application potential in nonemission display field.