01789nas a2200205   4500008004100000245005300041210005300094260001200147300001000159490000800169520118600177653001801363653002901381653001901410653001901429100002301448700002301471700001701494856007201511       1996                        eng d00aOptical Indices of Electrochromic Tungsten Oxide0 aOptical Indices of Electrochromic Tungsten Oxide  c08/1997  a10-160 v3063 a<p>Tungsten trioxide (WO<sub>3</sub>) is the most widely used material for the active layer of electrochromic devices. Knowledge of the complex refractive index over the range of coloration states is required for device design. Optical constants of WO<sub>3</sub> over the whole solar spectrum were determined as a function of injected charge. Films of WO<sub>3</sub> were prepared by electron-beam evaporation, then colored in several steps by reduction with lithium (Li) up to 68 mC cm<sup>-2</sup> µm<sup>-1</sup> injected charge. Measurements included variable-angle spectroscopic ellipsometry and spectroscopic transmittance and reflectance at normal incidence. Analysis was complicated by the fact that a transparent-conducting layer of indium tin oxide (ITO) was required to perform lithiation. Optical indices of the glass substrate and ITO transparent conductor were determined separately and then fixed in the model. The indices of WO<sub>3</sub> could then be extracted from measurements on the complete structure. A parametric dispersion model corresponding to Gaussian broadening of the oscillators was used to represent the dielectric response of WO<sub>3</sub>.</p>10aColored state10aComplex refractive index10aelectrochromic10atungsten oxide1 avon Rottkay, Klaus1 aRubin, Michael, D.1 aWen, Shi-Jie  uhttps://facades.lbl.gov/publications/optical-indices-electrochromic02176nas a2200181   4500008004100000245005500041210005500096260001200151300001000163490000700173520164100180100002301821700002301844700001701867700001901884700002401903856006701927       1996                        eng d00aOptical Indices of Lithiated Electrochromic Oxides0 aOptical Indices of Lithiated Electrochromic Oxides  c07/1998  a49-570 v543 a<p>Optical indices have been determined for thin films of several electrochromic oxide materials. One of the most important materials in electrochromic devices, WO<sub>3</sub>, was thoroughly characterized for a range of electrochromic states by sequential injection of Li ions. Another promising material, Li<sub>0.5</sub>Ni<sub>0.5</sub>O, was also studied in detail. Less detailed results are presented for three other common lithium-intercalating electrochromic electrode materials: V<sub>2</sub>O<sub>5</sub>, LiCoO<sub>2</sub>, and CeO<sub>2</sub>-TiO<sub>2</sub>. The films were grown by sputtering, pulsed laser deposition (PLD) and sol-gel techniques. Measurements were made using a combination of variable-angle spectroscopic ellipsometry and spectroradiometry. The optical constants were then extracted using physical and spectral models appropriate to each material. Optical indices of the underlying transparent conductors, determined in separate studies, were fixed in the models of this work. The optical models frequently agree well with independent physical measurements of film structure, particularly surface roughness by atomic force microscopy. Inhomogeneity due to surface roughness, gradient composition, and phase separation are common in both the transparent conductors and electrochromics, resulting sometimes in particularly complex models for these materials. Complete sets of data are presented over the entire solar spectrum for a range of colored states. This data is suitable for prediction of additional optical properties such as oblique transmittance and design of complete electrochromic devices.</p>1 aRubin, Michael, D.1 avon Rottkay, Klaus1 aWen, Shi-Jie1 aÖzer, Nilgün1 aSlack, Jonathan, L.  uhttps://facades.lbl.gov/publications/optical-indices-lithiated