LAUSR

Herein, we report the investigations on the electrochromic properties of nebulized-spray deposited Mn3O4 thin films in Na2SO4 aqueous solution as a function of molar concentration, for the first time. Phase analysis reveals that the films possess a tetragonal structure. From the Raman study, strong Mn2+ breathing vibration(in Mn-O) occurred in tetrahedral sites(of spinel Mn3O4). At 0.02 M, the film surface is covered with very-tiny particles with 84% highest optical transparency average. Both transmittance and absorbance related properties of electrochromic states are consider here, while introducing the notions of transmittance modulation(∆T), absorbance modulation(∆A), transmittance modulation efficiency(TME) and absorbance modulation efficiency(AME (or) coloration efficiency). When the concentration increases, the red shift was occurred at highest peaks of ∆T, ∆A, TME and AME with respect to the decrease in optical band gap. The maximum AME and TME of 25.064 cm2C-1 (at 369.1 nm) and 17.542 cm2C-1(at 438.6 nm) were obtained for prepared samples. After the 100th cycle, the average AME(and TME)values in the UV and visible regions are decreases from 18.910 to 2.783 cm2C-1(2.884 to 1.060 cm2C-1) and from 11.089 to 4.772 cm2C-1(11.346 to 4.684 cm2C-1), respectively, indicating that the film is electrochromically active in the visible region even after the 100th cycle.