| Summary: | 碩士 === 國立成功大學 === 化學工程研究所 === 83 === A solid-state electrochromic system is presented. It is
transparent and comprised of a tungsten oxide and Prussian
blue (PB) thin film or its analog couple in combination with a
proton- conducting, solid-polymer electrolyte. Tungsten oxide
thin films have been electrodeposited on TO glass. PB thin
films have been deposited by electrodeposition-galvanostatic
(ED-G) method. The transparent electrolyte is poly(2-
acrylamido-2-methylpropane sulfonic acid), or Poly-AMPS, which
was prepared by UV polymeriz- ation. The tungsten oxide
thin films, which were prepared potentiostatically
between －0.35 ∼ －0.45V vs. Ag/AgCl and maintained charge
density below 600 mC/cm2 show have enough stability
after 1,000 cycles. The transmittance difference measured
at wavelength of 550 nm was greater than 75％. The show
increasing absorption capability by higher potentials, the
films suffered degradation due to hydrogen evolution. When
potential is more negative than －0.4V(vs. Ag/AgCl). The WO3/
Poly-AMPS/PB devices were operated at low applied voltages,
＋1.2V to darken and －0.6V to bleach. The response time
was 20s for bleaching, and 17s for darkening when the
devices size was 5cm × 5cm. The coloration efficiency of
the device is measured to be 53.9 cm2/C at 550nm. Two factors
mainly responsible for the lack of electrochemical stability
for the complementary device of WO3/Poly-AMPS/PB. Namely,
the oxygen-containing polymer electrolyte and the charge
imbalance between WO3 and PB electrodes. By substitating PB
electrode with a PB analog, the indium hexacyanoferrate(
InHCF),the device WO3/Poly-AMPS/InHCF apparently accomplishes
higher cycling stability. This is because there is no need to
precharge WO3 and thus preventing charge loss from the WO3
electrode.
|
|---|
