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.