A coaxial-type pulsed arc plasma doping process for the lithium-ion thin-film electrolyte application

A combinatorial lithium-ion thin-film electrolyte deposition process that uses different types of arc plasma sources has been developed for thin-film inorganic complementary electrochromic devices (ECDs). With the coaxial-type pulsed arc plasma doping process, the lithium doping tantalum pentoxide (Ta2O5:Li) thin-film electrolyte doped with two different frequencies has been investigated. Although a lower ion conductivity of 9.30x10(-9) S/cm has been obtained with the Ta2O5:Li doped with the arc discharge frequency of 1Hz than the arc discharge frequency of 4Hz, the ECD has demonstrated a better optical modulation (Delta T) of 58.25%. To analyze the detailed material characteristic, the ion mobility and concentration have also been extracted from the Li drift current by the current-voltage (I-V) measurement with the isothermal transient ionic current method. The optimal Ta2O5:Li doped with the arc discharge frequency of 1Hz has demonstrated a higher ion mobility of 8.22x10(-10) cm(2)/Vs and a lower concentration of 7.07x10(19)cm(-3). As a result, the electrolyte with higher ion mobility and lower concentration is more important than the higher ion conductivity for ECD applications.