01366nas a2200169 4500008004100000022001500041245010600056210006900162260001200231300001200243490000700255520079100262100002301053700002301076700002101099856007601120 1999 eng d a0021-8979 00aRefractive Index Changes of Pd-Coated Magnesium Ianthanide Switchable Mirrors Upon Hydrogen Insertion0 aRefractive Index Changes of PdCoated Magnesium Ianthanide Switch c01/1999 a408-4130 v853 a

The optical effect upon insertion of hydrogen into Pd-coated magnesium lanthanide switchable mirrors is investigated in terms of the changes of their complex refractive indices. A significant change in the optical constants of LnMg layers is seen between the as-deposited state and the dehydrided state after one cycle. Furthermore, the optical effect of switching the Pd cap layer to a PdH cap layer was determined. It is shown that the Pd layer mainly limits the visible transmittance of the hydrided stack to about 35%-40%. Whereas the extinction coefficient of dehydrided LnMg layers at 550 nm is between 2.2 and 3.1, it is as low 10-4 as in the transparent state. This is of great promise to applications requiring large optical contrast (e.g., optical switches).

1 avon Rottkay, Klaus1 aRubin, Michael, D.1 aDuine, Peter, A. uhttps://facades.lbl.gov/publications/refractive-index-changes-pd-coated01659nas a2200193 4500008004100000050001500041245009400056210006900150260002500219520098200244100002301226700002301249700002101272700002501293700002701318700002401345700002101369856007501390 1998 eng d aLBNL-4227700aEffect of Hydrogen Insertion on the Optical Properties of PD-Coated Magnesium Lanthanides0 aEffect of Hydrogen Insertion on the Optical Properties of PDCoat aLondon, U.K.c9/19983 a

Metallic magnesium lanthanide thin films upon insertion of hydrogen transform to a highly transparent hydride phase. With a Pd overlayer, the transformation can be produced either by electrochemical insertion of hydrogen or by exposing the film to hydrogen gas. Unlike amorphous oxide electrochromics, the transformation is accompanied by a large change in visible reflectance (about 50%). The optical switching effect in these materials is investigated in terms of changes in the complex refractive index as determined by variable-angle spectroscopic ellipsometric and normal-incidence radiometric measurements over the solar spectrum. Furthermore the optical effect of converting the Pd caplayer to Pd-H was determined. It is shown that the pd layer limits the visible transmittance of the hyrdrided stack to about 35-40%. Whereas the extinction coefficient of the dehydrided LnMg-layers at 550 nm is between 2.2 and 3.1, it is as low as 10-4 in the transparent state.

1 avon Rottkay, Klaus1 aRubin, Michael, D.1 aMichalak, Franck1 aArmitage, Robert, D.1 aRichardson, Thomas, J.1 aSlack, Jonathan, L.1 aDuine, Peter, A. uhttps://facades.lbl.gov/publications/effect-hydrogen-insertion-optical02282nas a2200229 4500008004100000245008200041210006900123260001200192300001000204490000700214520155300221653002501774653002801799653001501827100002301842700001701865700002701882700001901909700002301928700002401951856007701975 1998 eng d00aElectrochromic lithium nickel oxide by pulsed laser deposition and sputtering0 aElectrochromic lithium nickel oxide by pulsed laser deposition a c07/1998 a59-660 v543 a

Thin films of lithium nickel oxide were deposited by sputtering and pulsed laser deposition (PLD) from targets of pressed LiNiO2 powder. The composition and structure of these films were analyzed using a variety of techniques, such as nuclear-reaction analysis, Rutherford backscattering spectrometry (RBS), X-ray diffraction, infrared spectroscopy, and atomic-force microscopy. Crystalline structure, surface morphology and chemical composition of LixNi1−xO thin films depend strongly on deposition oxygen pressure, temperature as well as substrate–target distance. The films produced at temperatures lower than 600°C spontaneously absorb CO2 and H2O at their surface once they are exposed to the air. The films deposited at 600°C proved to be stable in air over a long period. Even at room temperature the PLD films are denser and more stable than sputtered films. RBS determined the composition of the best films to be Li0.5Ni0.5O deposited by PLD at 60 mTorr O2 pressure. Electrochemical tests show that the films exhibit excellent reversibility in the range 1.0–3.4 V versus lithium. Electrochemical formatting which is used to develop electrochromism in other films is not needed for the stoichiometric films. The optical transmission range is almost 70% at 550 nm for 150 nm-thick films. Devices made from these films were analyzed using novel reference electrodes and by disassembling after cycling.

10aLithium nickel oxide10apulsed laser deposition10asputtering1 aRubin, Michael, D.1 aWen, Shi-Jie1 aRichardson, Thomas, J.1 aKerr, John, B.1 avon Rottkay, Klaus1 aSlack, Jonathan, L. uhttps://facades.lbl.gov/publications/electrochromic-lithium-nickel-oxide01510nas a2200181 4500008004100000050001500041245010000056210006900156300001400225490000700239520088500246100002101131700002301152700002701175700002401202700002301226856007901249 1998 eng d aLBNL-4227600aElectrochromic Lithium Nickel Oxide Thin Films by RF-Sputtering from a LiNiO2 Target0 aElectrochromic Lithium Nickel Oxide Thin Films by RFSputtering f a3085-30920 v443 a

Thin films of lithium nickel oxide were deposited by rf sputtering from a stoichiometric LiNiO2 target. The composition and structure of these films depended on the oxygen pressure during deposition (sputtering gas is Argon), and, to a certain extent, the target history. The sputtering geometry, i.e. the substrate to target distance and the sputtering angle were also critical. the films exhibit excellent reversibility in the potential range 1.1V to 3.8 V vs Li/Li+ and could be cycled in a liquid electrolyte half cell for more than 3000 cycles with a switching range ΔTvis close to 70%. The coloration efficiency in the visible was typically -30 to -40 cm2 C-1. The switching performance of a device utilizing a lithium nickel oxide film as counter electrode for a tungsten oxide electrochromic film is reported.

1 aMichalak, Franck1 avon Rottkay, Klaus1 aRichardson, Thomas, J.1 aSlack, Jonathan, L.1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/electrochromic-lithium-nickel-oxide-101800nas a2200169 4500008004100000050001500041245016500056210006900221300001400290490000700304520115200311100002001463700002501483700002301508700002301531856007601554 1998 eng d aLBNL-4182000aEllipsometry on Sputter Deposited Tin Oxide Films: Optical Constants Versus Stoichiometry Hydrogen Content, and Amount of Electrochemically Intercalated Lithium0 aEllipsometry on Sputter Deposited Tin Oxide Films Optical Consta a7734-77410 v373 a

Tin oxide thin films were deposited by reactive radio-frequency magnetron sputtering onto In2O3:Sn coated and bare glass substrates. Optical constants in the 300-2500 nm wavelength range were determined by a combination of variable-angle spectroscopic ellipsometry and spectrophotometric transmittance measurements. Surface roughness was modeled from optical measurements and compared with atomic-force microscopy. The two techniques gave consistent results. The fit between experimental optical data and model results could be significantly improved when it was assumed that the refractive index of the Sn oxide varied across the film thickness. Varying the oxygen partial pressure during deposition made it possible to obtain films whose complex refractive index changed at the transition from SnO to SnO2. An addition of hydrogen gas during sputtering led to lower optical constants in the full spectral range in connection with a blue shift of the band gap. Electrochemical intercalation of lithium ions into the Sn oxide films raised their refractive index and enhanced their refractive-index gradient.

1 aIsidorsson, Jan1 aGranqvist, Claes, G.1 avon Rottkay, Klaus1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/ellipsometry-sputter-deposited-tin01350nas a2200181 4500008004100000245007700041210006900118260001200187300001400199490000700213520076000220100002100980700001901001700002501020700002301045700002301068856007701091 1998 eng d00aOptical Constants of Sputter-Deposited Ti-Ce Oxide and Zr-Ce Oxide Films0 aOptical Constants of SputterDeposited TiCe Oxide and ZrCe Oxide  c09/1998 a5993-60010 v373 a

Films of Ti oxide, Zr oxide, Ce oxide, Ti-Ce oxide, and Zr-Ce oxide were made by means of reactive dc magnetron sputtering in a multitarget arrangement. The films were characterized by x-ray diffraction and electrochemical measurements, both techniques being firmly connected to stoichiometric information. The optical constants n and k were evalued from spectrophotometry and from variable-angle spectroscopic ellipsometry. The two analyses gave consistent results. It was found that n for the mixed-oxide films varied smoothly between the values for the pure oxides, whereas k in the band-gap range showed characteristic differences between Ti-Ce oxide and Zr-Ce oxide. It is speculated that this difference is associated with structural effects.

1 aVeszelei, Monica1 aKullman, Lisen1 aGranqvist, Claes, G.1 avon Rottkay, Klaus1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/optical-constants-sputter-deposited01511nas a2200181 4500008004100000050001500041245007100056210006900127260002400196490001000220520090600230100002701136700002301163700002401186700002101210700002301231856007501254 1998 eng d aLBNL-4238100aTungsten-Vanadium Oxide Sputtered Films for Electrochromic Devices0 aTungstenVanadium Oxide Sputtered Films for Electrochromic Device aBoston, MAc11/19980 v98-263 a

Mixed vanadium and tungsten oxide films with compositions ranging from 0 to 100% vanadium (metals basis) were prepared by reactive sputtering from metallic vanadium and tungsten targets in an atmosphere of argon and oxygen. The vanadium content varied smoothly with the fraction of total power applied to the vanadium target. Films containing vanadium were more color neutral than pure tungsten oxide films, tending to gray-brown at high V fraction. The electrochromic switching performance of these films was investigated by in situ monitoring of their visible transmittance during lithium insertion/extraction cycling in a non-aqueous electrolyte (1M LiClO4 in PC). the solar transmittance and reflectance was measured ex-situ. Films with vanadium content greater than about 15%, exhibited a marked decrease in switching range. The coloration efficiencies followed a similar trend.

1 aRichardson, Thomas, J.1 avon Rottkay, Klaus1 aSlack, Jonathan, L.1 aMichalak, Franck1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/tungsten-vanadium-oxide-sputtered02100nas a2200169 4500008004100000050001500041245008300056210006900139300001000208490001200218520153600230100002301766700001901789700002301808700002701831856007201858 1997 eng d aLBNL-4009600aAnalysis of Binary Electrochromic Tungsten Oxides with Effective Medium Theory0 aAnalysis of Binary Electrochromic Tungsten Oxides with Effective a50-550 v308-3093 a

Multicomponent oxides are of increasing interest for electrochromic electrodes. To reduce the large number of permutations in composition it would be useful to be able to predict the properties of the mixtures from the pure oxide components. WO3 mixed with V2O5 has been produced by a sol-gel technique in order to increase durability and color neutrality of conventional WO3 electrochromic coatings. Chemical composition was confirmed by Rutherford backscattering spectrometry (RBS). Surface morphology was analyzed by atomic force microscopy (AFM). Electrochromic performance of the films was tested by cyclic voltammetry with in-situ transmission control. Optical constants of vanadium tungsten oxides were determined over the whole solar spectrum. The measurements included variable angle spectroscopic ellipsometry and spectral transmittance and reflectance. An attempt is made to treat doped tungsten oxide as an effective medium consisting of a mixture of WO3 with V2O5. In the clear state, comparison of optical constants and thickness directly determined on the samples yields qualitative agreement with results from effective-medium analysis. The resulting component fraction also agrees as long as the film density does not deviate too much from the linearly interpolated value between the pure components. For the colored state, preferential trapping of electrons at one atom species hinders the application of effective medium theory.

1 avon Rottkay, Klaus1 aÖzer, Nilgün1 aRubin, Michael, D.1 aRichardson, Thomas, J. uhttps://facades.lbl.gov/publications/analysis-binary-electrochromic02057nas a2200229 4500008004100000050001500041245011100056210006900167260002700236300001100263490000900274520128000283653002601563653002801589653001901617653002201636100002301658700002701681700002301708700002401731856007201755 1997 eng d aLBNL-4066800aEffective Medium Approximation of the Optical properties of electrochromic cerium-titanium oxide compounds0 aEffective Medium Approximation of the Optical properties of elec aSan Diego, CAc07/1997 a19-Sep0 v31383 a

Cerium titanium oxide samples derived from a solution have been compared against sputtered films over a wide range of different compositions. X-ray diffraction was used to investigate the structural properties of the compound material existing in a two-phase mixture MAO2-MBO2. The optical properties were evaluated over the whole solar spectrum by variable angle spectroscopic ellipsometry combined with spectrophutometry. The spectral complex refractive index was determined for CeO2 and TiO2, as well as for their compounds. To reduce the large number of permutations in composition of multi-component oxides it would be useful to be able to predict the properties of the mixtures from the pure oxide components. Therefore these results were compared to those obtained by effective medium theory utilizing the optical constants of CeO2 and TiO2. In order to investigate the performance as passive counter-electrode in Li+ based electrochromic devices the films were tested by cyclic voltammetry with in-situ transmission control. Chemical composition was measured by Rutherford backscattering spectrometry. Surface morphology was analyzed by atomic force microscopy.

10acerium titanium oxide10aeffective medium theory10aelectrochromic10aoptical constants1 avon Rottkay, Klaus1 aRichardson, Thomas, J.1 aRubin, Michael, D.1 aSlack, Jonathan, L. uhttps://facades.lbl.gov/publications/effective-medium-approximation01883nas a2200253 4500008004100000050001500041245008500056210006900141260003000210520107000240653001301310653002001323653004101343653001501384653002201399653001801421653000901439100002301448700002701471700002301498700002401521700001901545856006501564 1997 eng d aLBNL-4155000aInfluence of stoichiometry on the electrochromic cerium-titanium oxide compounds0 aInfluence of stoichiometry on the electrochromic ceriumtitanium  aHonolulu, Hawaiic11/19973 a

CeO2-TiO2 finds use as passive counter-electrode in electrochromic devices. Thin films were produced by dc-sputtering in a wide range of compositions. Influence of total pressure and oxygen partial pressure on the optical constants of TiO2 was investigated. Slightly substoichiometric TiO2 films exhibit a red-shift of the bandgap. The TiO2 content in the compound essentially determines the degree of cathodical coloring upon Li+ intercalation. However, pure TiO2 films with comparable visible transmittance in the clear state behave differently during electrochemical cycling depending on oxygen stoichiometry. Films that are deposited at higher total pressure are more oxygen rich and require initial formatting until current voltage cycles become stable. CeO2-TiO2 films of intermediate compositions have the relatively highest charge capacity. Comparison with atomic force microscopy indicates a correlation of small grain size with high charge capacity.

10aband gap10acharge capacity10aelectrochromic cerium titanium oxide10agrain size10aoptical constants10arms roughness10atio21 avon Rottkay, Klaus1 aRichardson, Thomas, J.1 aRubin, Michael, D.1 aSlack, Jonathan, L.1 aKullman, Lisen uhttps://facades.lbl.gov/publications/influence-stoichiometry01552nas a2200157 4500008004100000050001500041245001800056210001800074300001200092490000700104520116200111100002301273700002301296700002001319856005501339 1997 eng d aLBNL-3991100aWindow Optics0 aWindow Optics a149-1610 v623 a

Optical and radiative properties of glazing materials are primary inputs for determination of energy performance in buildings. This paper revisits the problem and reformulates the calculations to encompass a variety of solutions to practical problems in window optics. Properties of composite systems such as flexible films applied to rigid glazing and laminated glazing can be predicted from measurements on isolated components in air or other gases. Properties of a series of structures can be generated from those of a base structure. For example, the measured properties of a coated or uncoated substrate can be extended to a range of available substrate thicknesses without the need to measure each thickness. Similarly, a coating type could be transferred by calculation to any other substrate. A simple monolithic model for extrapolating from normal properties to oblique properties is shown to have sufficient accuracy for the purpose of annual energy performance calculations. A process is initiated to develop a reliable method for determination of effective indices suitable for more detailed spectral and directional optical calculations.

1 aRubin, Michael, D.1 avon Rottkay, Klaus1 aPowles, Rebecca uhttps://facades.lbl.gov/publications/window-optics01836nas a2200169 4500008004100000050001500041245008800056210006900144260002700213520124400240100001701484700001901501700002301520700002401543700002301567856007601590 1996 eng d aLBNL-3963300aAnalysis of Durability in Lithium Nickel Oxide Electrochromic Materials and Devices0 aAnalysis of Durability in Lithium Nickel Oxide Electrochromic Ma aSan Diego, CAc10/19963 a

Thin films of lithium nickel oxide were deposited by sputtering and laser ablation from targets of pressed nickel oxide and lithium oxide powders. These films were assembled into electrochromic test devices with tungsten oxide as the opposite electrode and a polymer electrolyte. Analysis of the failure modes was carried out at several levels: The composition and structure of the films were examined before and after cycling using a variety of techniques, such as infrared spectroscopy, nuclear-reaction analysis, Rutherford backscattering spectrometry, x-ray diffraction and atomic force microscopy. Absorption of water vapor was found to be a major factor determining the cyclic stability of the films. A new technique is described for incorporating reference electrodes made from an electronically isolated corner into devices. This structure enabled identification of potential problems associated with a particular interface. Finally, some of the devices were disassembled and the components examined. For example, a small quantity of the polymer was extracted and studied by gas chromatography and mass spectroscopy. Small organic fragments were discovered which correspond to expected weak points in the polymer structures.

1 aWen, Shi-Jie1 aKerr, John, B.1 aRubin, Michael, D.1 aSlack, Jonathan, L.1 avon Rottkay, Klaus uhttps://facades.lbl.gov/publications/analysis-durability-lithium-nickel02253nas a2200169 4500008004100000050001500041245007700056210006900133260002900202300001000231490001000241520169000251100001701941700002301958700002301981856007902004 1996 eng d aLBNL-3959300aElectrochromic Lithium Nickel Oxide Thin Film by Pulsed Laser Deposition0 aElectrochromic Lithium Nickel Oxide Thin Film by Pulsed Laser De aSan Antonio, TXc10/1996 a54-630 v96-243 a

Thin films of lithium nickel oxide were deposited by pulsed laser deposition (PLD) from targets of pressed LiNiO2 powder with layered structure. The composition, structure and surface air sensitivity of these films were analyzed using a variety of techniques, such as nuclear reaction analysis, Rutherford backscattering spectrometry (RBS), x-ray diffraction, infrared spectroscopy, and atomic force microscopy. Optical properties were measured using a combination of variable angle spectroscopic ellipsometry and spectroradiometry. Crystalline structure, surface morphology and chemical composition of LixNi1-xO thin films depend strongly on deposition oxygen pressure, temperature as well as substrate target distance. The films produced at temperatures lower than 600 °C spontaneously absorb CO2 and H2O at their surface once they are exposed to the air. The films deposited at 600 °C proved to be stable in air over a long period. Even when deposited at room temperature the PLD films are denser and more stable than sputtered films. RBS determined that the best electrochromic films had the stoichiometric composition Li0.5Ni0.5O when deposited at 60 mTorr O2 pressure. Electrochemical tests show that the films exhibit excellent reversibility in the range 1.0 V to 3.4 V versus lithium and long cyclic life stability in a liquid electrolyte half cell. Electrochemical formatting which is used to develop electrochromism in other films and nickel oxide films is not needed for these stoichiometric films. The optical transmission range is almost 70% at 550 nm for 120 nm thick films.

1 aWen, Shi-Jie1 avon Rottkay, Klaus1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/electrochromic-lithium-nickel-oxide-001789nas a2200205 4500008004100000245005300041210005300094260001200147300001000159490000800169520118600177653001801363653002901381653001901410653001901429100002301448700002301471700001701494856007201511 1996 eng d00aOptical Indices of Electrochromic Tungsten Oxide0 aOptical Indices of Electrochromic Tungsten Oxide c08/1997 a10-160 v3063 a

Tungsten trioxide (WO3) 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 WO3 over the whole solar spectrum were determined as a function of injected charge. Films of WO3 were prepared by electron-beam evaporation, then colored in several steps by reduction with lithium (Li) up to 68 mC cm-2 µm-1 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 WO3 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 WO3.

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

Optical indices have been determined for thin films of several electrochromic oxide materials. One of the most important materials in electrochromic devices, WO3, was thoroughly characterized for a range of electrochromic states by sequential injection of Li ions. Another promising material, Li0.5Ni0.5O, was also studied in detail. Less detailed results are presented for three other common lithium-intercalating electrochromic electrode materials: V2O5, LiCoO2, and CeO2-TiO2. 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.

1 aRubin, Michael, D.1 avon Rottkay, Klaus1 aWen, Shi-Jie1 aÖzer, Nilgün1 aSlack, Jonathan, L. uhttps://facades.lbl.gov/publications/optical-indices-lithiated01218nas a2200145 4500008004100000050001400041245004900055210004800104260003100152490000800183520075800191100002300949700002300972856007700995 1996 eng d aLBL-3858600aOptical Indices of Pyrolitic Tin-Oxide Glass0 aOptical Indices of Pyrolitic TinOxide Glass aSan Francisco, CAc04/19960 v4263 a

SnO2:F is a widely used transparent conductor and commercially available in a multilayer structure as Tech glass. Current applications include photovoltaics, electrochromics and displays. Optical design of these and other applications requires knowledge of the optical constants, in some cases, over the whole solar spectrum. Various optical property measurements were performed including variable angle spectroscopic ellipsometry, and spectral transmittance and reflectance measurements. This material is deposited in several steps and has a fairly complex structure. The measured data were fit to models based on this structure to obtain the optical indices. Atomic force microscopy confirmed the optically modeled surface roughness.

1 avon Rottkay, Klaus1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/optical-indices-pyrolitic-tin-oxide01797nas a2200145 4500008004100000050001500041245005700056210005700113260002700170520132200197100002301519700002301542700001901565856006701584 1996 eng d aLBNL-3959400aOptical Modeling of a Complete Electrochromic Device0 aOptical Modeling of a Complete Electrochromic Device aSan Diego, CAc10/19963 a

Optical indices have been determined for thin films of all materials needed to model a typical electrochromic device. Two electrochromic materials, tungsten oxide and lithium nickel oxide, are widely used in electrochromic devices. The optical indices of the underlying transparent conductors as well as a polymer electrolyte were also analyzed. The optical data was obtained using a combination of variable-angle spectroscopic ellipsometry and spectroradiometry. The data was then fit to appropriate models of structure and dispersion in order to extract the optical indices of the materials. First, the optical indices of the transparent conductive substrates were obtained and fixed in the model. The best models correspond well to independent physical measurements of film structure, such as atomic-force microscopy and surface profiling. Surface roughness, gradient composition and other types of inhomogeneity are common in both the transparent conductors and electrochromic, resulting in particularly complex models. The polymer has a homogeneous structure, but obtaining optically smooth surfaces was a problem. Complete sets of data were produced over the entire solar spectrum for a range of colored states of the films. Using the data for each layer, a realistic electrochromic device was simulated.

1 avon Rottkay, Klaus1 aRubin, Michael, D.1 aKerr, John, B. uhttps://facades.lbl.gov/publications/optical-modeling-complete01683nas a2200157 4500008004100000050001400041245009300055210006900148300001200217490000800229520114900237100002301386700002301409700001901432856007401451 1995 eng d aLBL-3804200aOptical Indices of the Tin-doped Indium Oxide and Tungsten Oxide Electrochromic Coatings0 aOptical Indices of the Tindoped Indium Oxide and Tungsten Oxide  a551-5560 v4033 a

Thin films of tin-doped indium oxide are widely used for transparent conductors. One application of In2O3:Sn (ITO) is transparent contacts for electrochromic electrodes. Optical design of electrochromic devices requires knowledge of the optical constants for each layer from the near ultraviolet and visible to the mid infrared. Determination of the optical constants of the electrochromic layer cannot be made in isolation; a complete device or at least a half-cell including a layer of ITO is required to change the optical state of the electrochromic material. Measurements on ITO were made using variable-angle spectral ellipsometry, and spectral transmittance and reflectance. A series of structural models were fit to this data. The problem is complicated because of inhomogeneity in the films, variability in the manufacturing process, and sensitivity to environmental conditions. The spectral dependency was modeled by a single Lorentz oscillator and a Drude free-electron component. This data was then used as the basis for a model to extract the optical constants for a tungsten oxide electrochromic film.

1 avon Rottkay, Klaus1 aRubin, Michael, D.1 aÖzer, Nilgün uhttps://facades.lbl.gov/publications/optical-indices-tin-doped-indium