Operation mechanism investigation of electrochromic display using tungsten oxides based on solid-state metal-oxide-metal structures

摘要

In this work, we investigate the electrochromic effect of WO_3 electrochromic display device and operation mechanism based on a solid-state TaN/WO_3/ITO metal-oxide-metal capacitor. The electrochromic switching mechanism correlated with the oxygen vacancy concentration was proposed and well-predicted. The experimental results reveal that electrochromic device using electrodeposited WO_3 without post annealing exhibits the much better coloration and bleach process than those of annealed sample. The cycling test of WO_3 metal-oxide-metal capacitor also demonstrates that the degradations of current/voltage distributions are mainly originated from randomly distributed connected paths consisting of oxygen vacancies. Thus, oxygen vacancies formed during WO_3 electrodeposition process or post film annealing need to be well controlled.