External reflection tuning layers

Abstract

Window structures having a reflection tuning layer or reflection tuning layers are described herein.

Description

EXTERNAL REFLECTION TUNING LAYERSINCORPORATION BY REFERENCE

[0001] A PCT Request Form is filed concurrently with this specification as part of the present application. Each application that the present application claims benefit of or priority to as identified in the concurrently filed PCT Request Form is incorporated by reference herein in its entirety and for all purposes.BACKGROUND

[0002] Electrochromism is a phenomenon in which a material exhibits a reversible electrochemically-mediated change in an optical property when placed in a different electronic state, typically by being subjected to a voltage change. The optical property is typically one or more of color, transmittance, absorbance, and reflectance. One well known electrochromic material is tungsten oxide (WO3). Tungsten oxide is a cathodic electrochromic material in which a coloration transition, transparent to blue, occurs by electrochemical reduction. Electrochromic materials may be incorporated into, for example, windows for residential, commercial, and other uses.

[0003] The background description provided herein is for the purposes of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.SUMMARY

[0004] One aspect involves a window including: a transparent substrate; an electrochromic device; and a reflection tuning layer having a reflectance of about 20% to about 50% and a color characterized by an a* value of about -5 to about -3, and b* value of about -15 to about -5, whereby the transparent substrate, the electrochromic device, and the reflection tuning layer are disposed on a single lite.

[0005] In various embodiments, a* is about -4 to about -3.

[0006] In various embodiments, b* is about -11 to about -10.

[0007] In various embodiments, the reflection tuning layer is disposed between the transparent substrate and the electrochromic device.

[0008] In various embodiments, the transparent substrate is disposed between the reflection tuning layer and the electrochromic device.

[0009] In various embodiments, the window also includes a second reflection tuning layer, whereby the second reflection tuning layer has a color characterized by an a* value of about -5 to iabout -3, and b* value of about -15 to about -5. In some embodiments, the reflection tuning layer is disposed between the transparent substrate and the electrochromic device, and the transparent substrate is disposed between the reflection tuning layer and the second reflection tuning layer. In some embodiments, the reflection tuning layer and the second reflection tuning layer collectively have a reflectance of about 20% to about 50%.

[0010] In various embodiments, the window does not have a second transparent substrate.

[0011] In various embodiments, the window is not laminated.

[0012] In various embodiments, the reflection tuning layer includes one or more sublayers.

[0013] In various embodiments, the one or more sublayers includes a first sublayer having a first composition and a second sublayer having a second composition. In some embodiments, at least one of the one or more sublayers includes a metallic material. In some embodiments, the metallic layer includes aluminum, silver, gold, or copper.

[0014] In some embodiments, at least one of the one or more sublayers comprises an undoped semiconductor or insulator material. In some embodiments, the one of more sublayers includes a first sublayer including a semiconductor or conductor material and a second sublayer comprising an undoped semiconductor or insulator material. In some embodiments, the semiconductor, conductor, or insulator material includes In2O3, SnCh, ZnO, TiCh, SiCh, AI2O3, Ta20s, or ZrCh. In some embodiments, the semiconductor, conductor, or insulator material includes indium tin oxide, SnCh, ZnO, or InZnO.

[0015] In some embodiments, at least one of the one or more sublayers includes a semiconductor, conductor, or insulator material. In some embodiments, at least one of the one or more sublayers includes a high index material. In some embodiments, at least one of the one or more sublayers includes a low index material. In some embodiments, at least one of the one or more sublayers includes an adhesion layer.

[0016] In various embodiments, the first sublayer includes indium tin oxide, SnCh, ZnO, or InZnO, and the second sublayer comprises In2Os, SnO2, ZnO, TiO2, SiO2, AI2O3, Ta20s, or ZrO2.

[0017] In various embodiments, the window further includes a mate lite, wherein lite and mate lite are part of an insulating glass unit (IGU).

[0018] In various embodiments, the window further includes a titanium dioxide layer.

[0019] In various embodiments, the window further includes a silicon dioxide layer.

[0020] In various embodiments, the window further includes an adhesion layer.

[0021] These and other aspects are described further below with reference to the drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figures 1 A and IB depict the structure and function of electrochromic devices.

[0023] Figure 2 is a schematic illustration of a window structure having two reflection tuninglayers.

[0024] Figures 3 and 4 are schematic illustrations of windows having reflection tuning layers in accordance with certain disclosed embodiments.DETAILED DESCRIPTION

[0025] In the following description, numerous specific details are set forth to provide a thorough understanding of the presented embodiments. The disclosed embodiments may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail to not unnecessarily obscure the disclosed embodiments. While the disclosed embodiments will be described in conjunction with the specific embodiments, it will be understood that it is not intended to limit the disclosed embodiments.

[0026] Electrochromism is a phenomenon in which a material exhibits a reversible electrochemically mediated change in an optical property when placed in a different electronic state, typically by being subjected to a voltage change. Electrochromic materials may be incorporated into, for example, windows for residential, commercial, and other uses. The color, transmittance, absorbance, and / or reflectance of such windows may be changed by changing a feature of the electrochromic material, that is, electrochromic windows are windows that can be darkened or lightened electronically. A small voltage applied to an electrochromic device of the window will cause them to darken; reversing the voltage causes them to lighten. This capability allows control of the amount of light that passes through the windows and presents an opportunity for electrochromic windows to be used as energy-saving devices.

[0027] Aspect of this disclosure pertain to electrochromic windows that, when viewed from a building’s exterior, have aesthetically pleasing properties such uniform color within a window and uniform color from window-to-window. To achieve this, the windows have a simple structure that includes a reflection tuning layer. This layer reduces or eliminate non-uniform color within a window due to iridescence and window-to-window color variation due to different electrochromic tint states exhibiting different colors.MAJOR COMPONENTS OF A WINDOW

[0028] The main components of a window in accordance with this disclosure are:1. a transparent substrate such as a glass or plastic material2. an electrochromic device3. a reflection tuning layer

[0029] A transparent substrate provides structural support for the window. It may be a glass or plastic sheet. The electrochromic device can reversibly change tint state in response to applied electrical current or potential. While this disclosure refers to electrochromic devices, it should beunderstood that the reflection tuning aspects of the disclosure may be applied to any controllable thin film optically switchable device or electrically controllable optical device. As indicated, the reflection tuning layer may be used to establish a uniform external appearance of the window when it is fitted into a building or structure of choice.ELECTROCHROMIC DEVICE

[0030] An electrochromic device may have four or five layers. The outside-most layers of the electrochromic device may be transparent conductive layers such as transparent conductive oxides such as indium tin oxide and fluorinated tin oxide. Adjacent to the transparent conductive layers are two electrodes, at least one of which tints and clears in response to applied electrical potentials. In a typical embodiment, one of the electrodes is an anodically tinting electrode and the other is a cathodically tinting electrode. Optionally, in some embodiments, there is an ionically conductive layer between the two electrodes.

[0031] Examples of electrochromic device structure and fabrication will be presented. Figures 1A and IB are schematic cross-sections of an electrochromic device, 100, showing a common structural motif for such devices. Electrochromic device 100 includes a substrate 102, a conductive layer (CL) 104, an electrochromic layer (EC) 106, an optional ion conducting (IC) (electronically resistive) layer 108, a counter electrode layer (CE) 110, and another conductive layer (CL) 112. Elements 104, 106, 108, 110, and 112 are collectively referred to as an electrochromic (EC) stack, 114. A voltage source, 116, operable to apply an electric potential across electrochromic stack 114 effects the transition of the electrochromic device from, e.g., a bleached state (refer to Figure 1 A) to a colored state (refer to Figure IB).

[0032] The order of layers may be reversed with respect to the substrate. That is, the layers may be in the following order: substrate, conductive layer, counter electrode layer, ion conducting layer, electrochromic material layer, and conductive layer. The counter electrode layer may include a material that is electrochromic or not. If both the electrochromic layer and the counter electrode layer employ electrochromic materials, one of them should be a cathodically coloring material and the other should be an anodically coloring material. For example, the electrochromic layer may employ a cathodically coloring material and the counter electrode layer may employ an anodically coloring material. This is the case when the electrochromic layer is a tungsten oxide and the counter electrode layer is a nickel tungsten oxide.

[0033] The conductive layers commonly comprise transparent conductive materials, such as metal oxides, alloy oxides, and doped versions thereof, and are commonly referred to as “TCO” layers because they are made from transparent conducting oxides. In general, however, the transparent layers can be made of any transparent, electronically conductive material that iscompatible with the device stack. Some glass substrates are provided with a thin transparent conductive oxide layer such as fluorinated tin oxide, sometimes referred to as “TEC.”

[0034] Device 100 is presented for illustrative purposes only, in order to facilitate understanding of the context of embodiments described herein. Methods and apparatus described herein are used to identify and reduce defects in electrochromic devices, regardless of the structural arrangement of the electrochromic device.

[0035] During normal operation, an electrochromic device such as device 100 reversibly cycles between a bleached state and a colored state. As depicted in Figure 1 A, in the bleached state, a potential is applied across the electrodes (transparent conductor layers 104 and 112) of electrochromic stack 114 to cause available ions (e.g. lithium ions) in the stack to reside primarily in the counter electrode 110. If electrochromic layer 106 contains a cathodically coloring material, the device is in a bleached state. In certain electrochromic devices, when loaded with the available ions, counter electrode layer 110 can be thought of as an ion storage layer.

[0036] Referring to Figure IB, when the potential on the electrochromic stack is reversed, the ions are transported across ion conducting layer 108 to electrochromic layer 106 and cause the material to enter the colored state. Again, this assumes that the optically reversible material in the electrochromic device is a cathodically coloring electrochromic material. In certain embodiments, the depletion of ions from the counter electrode material causes it to color also as depicted. In other words, the counter electrode material is anodically coloring electrochromic material. Thus, layers 106 and 110 combine to synergistically reduce the amount of light transmitted through the stack. When a reverse voltage is applied to device 100, ions travel from electrochromic layer 106, through the ion conducting layer 108, and back into counter electrode layer 110. As a result, the device bleaches.

[0037] Some pertinent examples of electrochromic devices are presented in the following US patent applications, each incorporated by reference in its entirety: US Patent Application No. 12 / 645,111, filed December 22, 2009; US Patent Application No. 12 / 772,055, filed April 30, 2010; US Patent Application No. 12 / 645,159, filed December 22, 2009; US Patent Application No. 12 / 814,279, filed June 11, 2010; US Patent Application No. 13 / 462,725, filed May 2, 2012; and US Patent Application No. 13 / 763,505, filed February 8, 2013.

[0038] Electrochromic devices such as those described in relation to Figures 1 A and IB are used in, for example, electrochromic windows. For example, substrate 102 may be architectural glass upon which electrochromic devices are fabricated. Architectural glass is glass that is used as a building material. Architectural glass is typically used in commercial buildings, but may also be used in residential buildings, and typically, though not necessarily, separates an indoor environment from an outdoor environment. In certain embodiments, architectural glass is at least20 inches by 20 inches, and can be much larger, e.g., as large as about 72 inches by 120 inches.TRANSPARENT SUBSTRATE

[0039] In various embodiments, the transparent substrate is generally transparent to optical wavelengths and is somewhat rigid. It may serve as a structural support in the window. The electrochromic device and the reflection tuning layer are typically too thin to provide such support.

[0040] Any material having suitable optical, electrical, thermal, and mechanical properties may be used as substrate 102 in Figure 1A. Such substrates include, for example, glass, plastic, and mirror materials.

[0041] In some embodiments, the substrate includes a glass such as a soda lime glass. A substrate may include one or more optional optical tuning and / or ion diffusion barrier layers. Examples of these include silica, titanium dioxide, and undoped tin oxide. Collectively, optical tuning and / or ion diffusion barrier layers may have a thickness of about 0-100 nm. One or more such layers may be employed. In some embodiments, such layers include at least a silica layer and an undoped tin oxide layer. In some embodiments, such layers include at least two separated silica layers.

[0042] The substrate may be of any thickness, as long as it has suitable mechanical properties to support the electrochromic stack 120. While the substrate 102 may be of any thickness or transparent material, in some embodiments, it is glass or plastic and is between about 0.01 mm and about 10 mm thick. In certain embodiments the substrate is glass that is between about 3 mm to 9 mm thick and may be tempered. In other embodiments, the glass may be very thin, between about 0.01 mm and 1 mm thick, or between about 0.1 mm and 1 mm thick, and be sodium-free or have very low sodium or other alkali content, e.g., substrates such as Coming, Incorporated’s (of Corning, New York) Gorilla®, Willow®, EagleXG®, or other similar glass substrates from commercial sources, such as those from Asahi Glass Corporation (AGC, of Tokyo, Japan).

[0043] In some embodiments of the invention, the substrate is architectural glass. Architectural glass is glass that is used as a building material. Architectural glass is typically used in commercial buildings, but may also be used in residential buildings, and typically, though not necessarily, separates an indoor environment from an outdoor environment. In certain embodiments, architectural glass is at least 20 inches by 20 inches, and can be much larger, e.g., as large as about 72 inches by 120 inches. Architectural glass is typically at least about 2 mm thick.

[0044] Examples include float glass and rigid transparent polymers such as polycarbonate and polymethylmethacrylate. If the transparent substrate is made of a silica glass, it is typically not tempered, although we should not exclude that possibility.

[0045] In some embodiments, a transparent substrate exhibits one or more of the followingmechanical properties, such as modulus of elasticity, hardness of the substrate, and thickness of the substrate.

[0046] A window in the context of this disclosure typically includes only a single transparent substrate. However, in some embodiments, a window may have multiple transparent substrates. For example, a window may comprise a laminated structure including two or more transparent substrates.OTHER LAYERS

[0047] A window, and particularly an electrochromic device on a window, may include one or more additional layers (not shown in Figure 1 A) such as one or more passive layers. Passive layers may improve certain optical properties may be included in electrochromic device. Passive layers for providing moisture or scratch resistance may also be included in the electrochromic device. For example, the conductive layers may be treated with anti -reflective or protective oxide or nitride layers. Other passive layers may serve to hermetically seal the electrochromic device.REFLECTION TUNING LAYER

[0048] In various embodiments, the reflection tuning layer is a material layer positioned adjacent to and second from an outside-facing transparent substrate, such that the reflection tuning layer is between the substrate and an electrochromic stack. In an alternative embodiment, the reflection tuning layer is on the outside facing surface of the transparent substrate, such that the transparent substrate is between the reflection tuning layer and the electrochromic device. In some cases, a window comprises two or more reflection tuning layers. For example, two reflection tuning layers may straddle a transparent substrate.

[0049] In various embodiments, the reflection tuning layer comprises an inorganic compound. Examples include metals, aluminum nitride, and titanium nitride. The reflection tuning layer has thickness and material properties selected to give appropriate optical properties (e.g., reflectance and color) and other layers can be included to modify the performance of the reflection tuning layer or to better integrate it with the rest of the stack.

[0050] In some embodiments, a reflection tuning layer comprises two or more sublayers. In some embodiments, the reflection tuning layer includes additional metallic or oxide layers that serve purposes beyond reflectivity or electrical conductivity, such as improving adhesion of the metal layer to adjacent layers, reducing interactions with adjacent layers (buffer layers), or blocking transport of materials into other layers (barrier layers).Reflectance and Color

[0051] Physical characteristics of a reflection tuning layer include reflectance and color. Reflectance may be given as the parameter %R, which is the fraction of incident light that isreflected back toward the source. Color may be defined by a color characteristic such as a position in the CIELAB color space, also referred to as L*a*b*.

[0052] In various embodiments, the reflection tuning layer may have a reflectance of at least about 20%, or at least about 30%, or less than about 60%, or less than about 50%.

[0053] When multiple reflection tuning layers are used in a single window, the overall reflectance value of these layers can be calculated from the optical properties of the individual reflection tuning layers. The reflectance of two separate reflection tuning layers is not merely the sum of the reflectances of the individual layers. The reflectance may be determined by using optical modeling software.

[0054] The color of a reflection tuning layer may be characterized by its a*and b* values. These values are values from the CIELAB color space defined by the International Commission on Illumination, whereby a* is mapped on an x-axis from negative (green) to positive (red) and b* is mapped on a y-axis from negative (blue) to positive (yellow). In certain embodiments, a reflection tuning layer’s a*and b* values are both negative, which means that the a*value is in the green region and the b* value is in the blue region.

[0055] In various embodiments, a reflection tuning layer may have a* value of about -5 to about -10, or -5 to about -3, or about -4 to about -3, or about -3 to about 0. In various embodiments, a reflection tuning layer may have a b* value of about -15 to about -5, or about -11 to about -10, or about -10 to about 0. In some embodiments, the reflection tuning layer has an a* value of about -5 to about -3, and b* value of about -15 to about -5. In some embodiments, the reflection tuning layer has an a* value of about -3 and b* value of about -10. In some embodiments, the reflection tuning layer has an a* value of about 0 and b* value of about 0.

[0056] In various embodiments, a reflection tuning layer may have a* value of about -10 to about +2.5. In various embodiments, a reflection tuning layer may have a b* value of about -20 to about +5. In some embodiments, the reflection tuning layer has an a* value of about -10 to about 0 and a b* value of about -15 to about -5.

[0057] In some embodiments, the reflection tuning layer includes a metal nitride material, such as aluminum nitride or titanium nitride. The thickness and material properties may be selected to give appropriate optical properties, such as reflectance and transmittance, and other layers may be included to modify the performance of the reflection tuning layer or to better integrate it with the rest of the layers in the overall stack.

[0058] In one example, an inorganic or ceramic reflection tuning layer is used. An inorganic or ceramic reflection tuning layer may be reflective but not a reduced or unreacted metal, but rather a compound with at least one more element. One example is titanium nitride (TiN), which is a compound of titanium and nitrogen that can be deposited using reactive sputtering or anotherdeposition technique such as atomic layer deposition or chemical vapor deposition. Titanium nitride may exhibit a yellow reflection, so other nitrides or oxides could be used (such as, but not limited to, AIN, TiAlN, and SiN). The reflectance of the reflection tuning layer may come from properties of the material itself but not necessarily from the geometry and properties of the layers around it. Layer thicknesses for initial deposition of the layer may be selected such that the metallic layer has preferred properties and thickness in the final device stack, accounting for chemical or physical changes that occur during later processing steps.

[0059] In a stack of layers, which is the case with windows of this disclosure, reflectance is influenced not only by intrinsic properties of the reflection tuning layer but also by adjacent layers. For example, the relative magnitudes of the refractive indices of two adjacent layers have an impact. When a first layer has a very low refractive index and second, adjacent layer has a very high refractive index, the interface between the layers will tend to be highly reflective. Thus, a reflection tuning layer may be viewed as a multi-layer reflective stack composed of (1) high transmission and low refractive index materials and / or (2) high transmission and high refractive index materials.

[0060] In some embodiments, a low refractive index material is silicon dioxide (SiCh). A low refractive index material may have a refractive index of less than about 1.7. Alternate materials may include magnesium fluoride (MgF).

[0061] A high refractive index material may have a refractive index of at least about 2.1. In some embodiments, a high refractive index material is titanium dioxide (Ti O2) . Alternate materials may include zinc oxide (ZnO), tantalum oxide (Ta20s), zinc sulfide (ZnS), or diamond-like carbon (DLC). These multilayer stacks take advantage of the high reflectivity that occurs at the interface between high index and low index materials. Additional repetitions of the high-low index material interface allow for enhancement and tuning of this reflection, but the initial embodiment uses a single high index layer in the “reflection tuning layer.”

[0062] In some embodiments, for low refractive index or high refractive index films with high transmittance, the material may have low absorption (A% = 100- %T - %R, where A is absorption, T is transmittance, and R is refraction). In some embodiments, materials absorb less than about 10%.Electrical Conductivity

[0063] In various embodiments, the reflection tuning layer has a particular electrical conductivity which depends on the material.Adhesion Function

[0064] The reflection tuning layer can function as an adhesion layer.Buffer Function

[0065] The reflection tuning layer may be used as a buffer layer.Barrier Function

[0066] The reflection tuning layer may be used as a barrier layer.High Transmission + Low Refractive Index

[0067] The reflection tuning layer have low refractive index and high transmission.High Transmission + High Refractive Index

[0068] The reflection tuning layer have high refractive index and high transmission.

[0069] Reflection tuning layers need not possess all their required properties until the window has been fully fabricated, including, for example, integrated in an IGU structure. Certain types of reflection tuning layers may oxidize or change properties during the manufacturing process, such as during tempering, deposition, or final anneal processes. Such changes may be accounted for when choosing the reflection tuning layer’s composition and initial properties.Window Appearance (Exterior)

[0070] To an observer outside a building having electrochromic windows, the windows may exhibit certain aesthetic qualities such as a consistent color over the face of any single window, a consistent color from window to window, even consistent color in different tint states, and a desirable color. However, it can be challenging to ensure that electrochromic windows are designed in a way that allows them to exhibit these properties.

[0071] A typical electrochromic window has thin layer components such as an electrochromic stack and reflection tuning layers. Because these layers often have a thickness close to the wavelengths of visible light, they can produce iridescence through constructive and destructive interference of light reflecting from adjacent material layers. The iridescence is manifest as different colors at different locations on the surface of a window. Such iridescence on a window surface appears similar to the iridescence produced by a layer of oil on water, which occurs by the same mechanism. Even slight differences in the thickness of a given layer of a window can introduce iridescence.

[0072] Additionally, the overall color of a given window may change depending on its tint state. Therefore, an outside observer might observe some windows in a first tint state having a first color and other windows a different tint state having a different color.WINDOW LAYER STRUCTURES

[0073] In the case of laminated windows, these issues may be addressed by introducing a reflection tuning layer such as illustrated in Figure 2. The reflection tuning layer has sufficient reflectance that color changes caused by iridescence or tint state are not seen by observers lookingat the building from outside the building. However, such laminated structures have an unnecessarily complicated structure.

[0074] Figure 2 shows an example layered structure that includes the reflection tuning layer. Figure 2 includes, from left to right (and from outside facing to inside facing), a glass layer which faces the outside of a building; a reflection tuning layer, an interlayer, a second glass layer, a second reflection tuning layer, a titanium oxide layer, an electrochromic (EC) stack, and an indium tin oxide (ITO) layer. The layers labeled “a” are layers intended to provide structural support. The “b” layers are layers used to manage reflection tuning to adjust the appearance of the window when viewed from outside of the building (from the left side of this cross sectional schematic illustration). The “c” layers in the EC stack are the layers that are optically switchable. Structures such as those shown in Figure 2 may have disadvantages in that they may be unnecessarily complicated.

[0075] Layered structures in accordance with certain disclosed embodiments have simpler structures. In certain embodiments of this disclosure, a window contains only a single transparent substrate. In certain embodiments of this disclosure, a window is not laminated. Note that laminated windows typically have to transparent substrates that are bonded to one another by a polymer adhesive. Examples are presented in U.S. Provisional Patent Application No. 63 / 430,156 filed on December 5, 2022, which is incorporated herein by reference in its entirety.

[0076] In various embodiments, the layered structure includes a glass layer on the outermost layer, a reflection tuning layer next, and an electrochromic stack (which may include a transparent ITO layer, optional TiO? or DMIL, counter electrode (CE) layer, optional ion-conducting (IC) layer, electrochromic (EC) layer, and a second ITO), and an ITO layer. In some embodiments, there may be additional layers between the reflection tuning layer and the electrochromic stack. For example, the order of layers may be as follows: reflection tuning layer, optional sodium blocking layer, fluorine-doped tin dioxide layer, titanium dioxide layer, then EC stack. In some embodiments, there may be additional layers between the reflection tuning layer and the electrochromic stack. For example, the order of layers may be as follows: reflection tuning layer, optional sodium blocking layer, fluorine-doped tin dioxide layer, then EC stack. In some embodiments, only one reflection tuning layer is present and it is located between the transparent substrate (or window) and the electrochromic device (or electrochromic stack). An example is shown in Figures 3 and 4. In another example, the glass layer and reflection tuning layer are switched such that the outermost layer facing the outside of a building is a reflection tuning layer, and the layer immediately adjacent to it from outside to inside is a glass layer, followed by an electrochromic stack (which may include a transparent ITO layer, optional TiO? or DMIL, CE layer, optional IC layer, EC layer, and a second ITO). In some embodiments, only one reflectiontuning layer is present and it is located on the surface facing the outside of a building and located on the transparent substrate (or window).

[0077] In various embodiments, the layered structure includes, from outside to inside, a reflection tuning layer, a glass layer, a second reflection tuning layer, and an electrochromic (EC) stack (which may include a transparent ITO layer, optional TiO? or DMIL, CE layer, optional IC layer, EC layer, and a second ITO). In some embodiments, there are two reflection tuning layers without an interlayer between them. In some embodiments, there are two reflection tuning layers where one is located on the outermost side of the transparent substrate and the other is located between the transparent substrate and the electrochromic device. Figure 4 shows an example.

[0078] In various embodiments, one or more defect mitigating insulating layers (DMILs) may be provided. In various embodiments, the titanium oxide layer in Figures 3 and 4 are DMILs. Such DMILs may be provided between the layers described in Figures 1 A, IB, 3, or 4, or within such layers. In some particular embodiments a DMIL may be provided between sublayers of a counter electrode layer, though DMILs can also be provided at alternative or additional locations. DMILs can help minimize the risk of fabricating defective devices. In certain embodiments, the insulating layer has an electronic resistivity of between about 1 and 5xlO10Ohm-cm. In certain embodiments, the insulating layer contains one or more of the following metal oxides: cerium oxide, titanium oxide, aluminum oxide, zinc oxide, tin oxide, silicon aluminum oxide, tungsten oxide, nickel tungsten oxide, tantalum oxide, and oxidized indium tin oxide. In certain embodiments, the insulating layer contains a nitride, carbide, oxynitride, or oxycarbide such as nitride, carbide, oxynitride, or oxycarbide analogs of the listed oxides. As an example, the insulating layer includes one or more of the following metal nitrides: titanium nitride, aluminum nitride, silicon nitride, and tungsten nitride. The insulating layer may also contain a mixture or other combination of oxide and nitride materials (e.g., a silicon oxynitride). DMILs are further described in U.S. Patent No. 9,007,674, which is herein incorporated by reference in its entirety.

[0079] In some embodiments, each reflection tuning layer includes two or more sub-layers. Collectively the sublayers impart a reflectance and a color to the window such that the collection of sublayers can act as a single reflection tuning layer.EXAMPLE STRUCTURES

[0080] Each option listed below lists the order of the stacks from the outermost layer (the layer facing an outside of a building) to the inside layer facing the interior of a building. Embodiments described herein are not limited to these examples.Option 1Glass / transparent substrateReflection Tuning LayerOptional sodium blocking layerOptional titanium dioxide layerOptional fluorine-doped tin oxide layerEC (electrochromic) stack (which may include ITO, optional TiO?, CE layer, optional IC layer,EC layer, and a second ITO)Option 2Reflection Tuning LayerGlass / transparent substrateOptional sodium blocking layerOptional titanium dioxide layerOptional fluorine-doped tin oxide layerEC (electrochromic) stack (which may include ITO, optional TiO?, CE layer, optional IC layer,EC layer, and a second ITO)Option 3Reflection Tuning LayerGlass / transparent substrateReflection Tuning LayerOptional sodium blocking layerOptional titanium dioxide layerOptional fluorine-doped tin oxide layerEC (electrochromic) stack (which may include ITO, optional TiO?, CE layer, optional IC layer,EC layer, and a second ITO)Option 4Glass / transparent substrateReflection Tuning Layer with these Sublayers:(which may be an optional sodium blocking layer)Adhesion layer (Ti, Cr, or Al)Metallic layer (Al, Ag, Au, or Cu)Adhesion layer (Ti, Cr, or Al)Semiconductor or conductor (ITO, SnO2, ZnO, or InZnO)EC (electrochromic) stack (which may include ITO, optional UO2, CE layer, optional IC layer, EC layer, and a second ITO)Option 5Glass / transparent substrateReflection Tuning Layer with these Sublayers:SiO? (which may be an optional sodium blocking layer)Adhesion layer (Ti, Cr, or Al)Metallic layer (Al, Ag, Au, or Cu)Adhesion layer (Ti, Cr, or Al)Undoped semiconductor or insulator (In2Os, SnO2, ZnO, UO2, SiO2, AI2O3, Ta20s, or ZrO2)Semiconductor or conductor (ITO, SnO2, ZnO, or InZnO)EC (electrochromic) stack (which may include ITO, optional UO2, CE layer, optional IC layer, EC layer, and a second ITO)Option 6Glass / transparent substrateReflection Tuning Layer with these Sublayers:SiO2SiO2 (which may be an optional sodium blocking layer)High index layer (TiO2)Low index layer (SiO2)Semiconductor or conductor (ITO, SnO2, ZnO, or InZnO)EC (electrochromic) stack (which may include ITO, optional TiO2 or DMIL, CE layer, optional IC layer, EC layer, and a second ITO)

[0081] An example of Option 1 is shown in Figure 3, which includes from left to right (and from the surface facing the exterior of a building on the left side, to surface facing interior of a building on the right side), a glass layer, reflection tuning layer, and an EC stack (which may include ITO, optional TiO2 or DMIL, CE layer, optional IC layer, EC layer, and a second ITO). In this example the glass layer is the layer on the outermost layer facing the exterior of a building.

[0082] An example of Option 2 from the surface facing the exterior of a building, to surface facing interior of a building may include a reflection tuning layer, a glass layer, and an EC stack (which may include ITO, optional TiO2 or DMIL, CE layer, optional IC layer, EC layer, and asecond ITO). In this example the reflection tuning layer is the layer on the outermost layer facing the exterior of a building.

[0083] An example of Option 3 is shown in Figure 4, which includes from left to right (and from the surface facing the exterior of a building on the left side, to surface facing interior of a building on the right side), a first reflection tuning layer, a glass layer, a second reflection tuning layer, and an EC stack (which may include ITO, optional TiCh or DMIL, CE layer, optional IC layer, EC layer, and a second ITO). In this example a first reflection tuning layer is the layer on the outermost layer facing the exterior of a building and an additional second reflection tuning layer is located between the glass layer and the EC stack.

[0084] In one example, the following layers may be present on a glass surface: a first layer having silicon oxide, a first optional adhesion layer having titanium, chromium, or aluminum, a nitride layer, a second optional adhesion layer, a semiconductor or conductor layer, and a defectmitigating insulating layer (DMIL). In various embodiments, the silicon oxide layer may have a thickness of greater than about 20 nm and less than about 200 nm. One function of the silicon oxide layer may be to block sodium. In various embodiments, the first adhesion layer may be a titanium, chromium, or aluminum layer having a thickness of about 1 nm to about 20 nm. In various embodiments, the nitride layer is an aluminum nitride layer, or a silver nitride layer, or a titanium nitride layer. For a titanium nitride layer, the thickness may be about 5 nm to about 100 nm, or about 10 nm to about 50 nm. In some embodiments, the initial layer thickness may be different to allow for oxidation during processing, which may cause an increase in layer thickness. In various embodiments, the second optional adhesion layer may have the same composition as or a different composition from the first optional adhesion layer. In various embodiments, the second optional adhesion layer may be a titanium layer, a chromium layer, or an aluminum layer. In some embodiments, the second optional adhesion layer may have a thickness of about 1 nm to about 20 nm. In some embodiments, the thickness of the second optional adhesion layer may be the same as or different from the thickness of the first optional adhesion layer. In various embodiments, the semiconductor or conductor layer is a transparent amorphous conductor layer. In various embodiments, the semiconductor layer or the conductor layer may be any one or more of the following materials: tin-doped indium oxide (ITO for short), doped or undoped tin oxide, doped or undoped zinc oxide, or indium zinc oxide. For ITO, the thickness may be about 10 nm to about 750 nm. In some embodiments, a thicker ITO may be used to have lower sheet resistance; however, a thicker ITO may also result in lower optical transmittance. In various embodiments, a doped tin oxide material may be doped with fluorine or antimony. A doped tin oxide material may have a thickness of about 10 nm to about 750 nm. In various embodiments, a doped zinc oxide material may be doped with gallium or aluminum. A doped zinc oxide material may have athickness of about 10 nm to about 750 nm. In some embodiments, an indium zinc oxide may have a thickness of about 10 nm to about 750 nm. In various embodiments, the DMIL may be titanium oxide, or titanium dioxide. In various embodiments, the DMIL may have a thickness of about 5 nm to about 30 nm.

[0085] In one example, a reflection tuning layer includes a conducting metal layer (Al, Ag, or other metal) with non-metallic layers on each side (oxides, nitrides, etc.). These can be deposited using chemical vapor methods (CVD, ALD) or physical vapor methods (sputtering, evaporation). Layer thicknesses may be selected such that the metallic layer has preferred properties and thickness in the final device stack, accounting for chemical or physical changes that occur during later processing steps. In one example, the reflection tuning layer includes sublayers, the sublayers being, from outer to inner layers, silicon oxide, first adhesion layer, metallic layer, second adhesion layer, and semiconductor or conductor layer. The semiconductor or conductor layer may be adjacent to a titanium oxide layer which may be a DMIL, which is adjacent to an EC stack and ITO layer.

[0086] The thickness of a silicon oxide layer may be greater than about 20 nm and less than about 200 nm. Each of the adhesion layers may be a titanium, chromium, or aluminum layer, which may have a thickness of about 1 nm to about 20 nm. The metallic layer may be aluminum, silver, gold, copper, titanium, or chromium. For aluminum metallic layers, the thickness may be about 5 nm to about 100 nm, or about 10 nm to about 30 nm. For silver metallic layers, the thickness may be about 5 nm to about 50 nm, or about 10 nm to about 30 nm. Additional silver thickness or treatment of the silver may be performed to account for oxidation or conductivity loss. Gold and copper may be used but the aesthetic of the window would not be a silver appearance. Chromium and titanium may be used but may have lower conductivity and could be more reactive. The semiconductor or conductor layer may be ITO, having a thickness of about 10 nm to about 750 nm, or tin oxide doped with fluorine or antimony having a thickness of about 10 nm to about 750 nm, or zinc oxide doped with gallium or aluminum having a thickness of about 10 nm to about 750 nm, or indium zinc oxide which is an amorphous transparent conductor material having a thickness of about 10 nm to about 750 nm. The titanium dioxide layer may be the DMIL having a thickness of about 5 nm to about 30 nm.

[0087] In some embodiments, the reflection tuning layer includes a metal layer that does not contribute to conductivity of the bottom contact of the device. In such embodiments, the layers may include that of Option 5 above whereby the undoped semiconductor or insulator layer may be any one or more of In2Os, SnO2, ZnO, TiO2, SiO2, AI2O3, Ta2Os, or ZrO2. The semiconductor or conductor layer may be ITO, having a thickness of about 10 nm to about 750 nm, or tin oxide doped with fluorine or antimony having a thickness of about 10 nm to about 750 nm, or zinc oxidedoped with gallium or aluminum having a thickness of about 10 nm to about 750 nm, or indium zinc oxide which is an amorphous transparent conductor material having a thickness of about 10 nm to about 750 nm. The titanium dioxide layer may be the DMIL having a thickness of about 5 nm to about 30 nm.

[0088] In some embodiments, the reflection tuning layer includes a high index material. Titanium oxide material may be a high index material. It may be deposited using reactive sputtering and generally adheres well to other materials. The layer thicknesses at point of initial deposition may be selected such that the metallic layer has preferred properties and thickness in the final device stack, accounting for chemical or physical changes that occur during later processing steps. The thickness of a high index material may be about 5 nm to about 100 nm. Precise layer thickness depends on managing TiCL properties as well as optimizing for interference effects. If a design with multiple high-low index transitions is used, then optical interference effects will be used to optimize reflectance across different wavelength ranges and incident angles. The high index material may be adjacent to a low index material such as silicon dioxide which may have a thickness of about 20nm to about 200 nm. This may be used in for example Option 6. The semiconductor or conductor layer may be ITO, having a thickness of about 10 nm to about 750 nm, or tin oxide doped with fluorine or antimony having a thickness of about 10 nm to about 750 nm, or zinc oxide doped with gallium or aluminum having a thickness of about 10 nm to about 750 nm, or indium zinc oxide which is an amorphous transparent conductor material having a thickness of about 10 nm to about 750 nm. The titanium dioxide layer may be the DMIL having a thickness of about 5 nm to about 30 nm.CONCLUSION

[0089] Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems, and apparatus of the present embodiments. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the embodiments are not to be limited to the details given herein.

Claims

CLAIMSWhat is claimed is:

1. A window compri sing : a transparent substrate; an electrochromic device; and a reflection tuning layer having a reflectance of about 20% to about 50% and a color characterized by an a* value of about -5 to about -3, and b* value of about -15 to about -5, wherein the transparent substrate, the electrochromic device, and the reflection tuning layer are disposed on a single lite.

2. The window of claim 1, wherein a* is about -4 to about -3.

3. The window of claim 1, wherein b* is about -11 to about -10.

4. The window of claim 1, wherein the reflection tuning layer is disposed between the transparent substrate and the electrochromic device.

5. The window of claim 1, wherein the transparent substrate is disposed between the reflection tuning layer and the electrochromic device.

6. The window of claim 1, further comprising a second reflection tuning layer, wherein the second reflection tuning layer has a color characterized by an a* value of about -5 to about -3, and b* value of about -15 to about -5.

7. The window of claim 6, wherein: the reflection tuning layer is disposed between the transparent substrate and the electrochromic device, and the transparent substrate is disposed between the reflection tuning layer and the second reflection tuning layer.

8. The window of claim 6, wherein the reflection tuning layer and the second reflection tuning layer collectively have a reflectance of about 20% to about 50%.

9. The window of claim 1, wherein the window does not have a second transparent substrate.

10. The window of claim 1, wherein the window is not laminated.

11. The window of claim 1, wherein the reflection tuning layer comprises one or more sublayers.

12. The window of claim 1, wherein the one or more sublayers comprises a first sublayer having a first composition and a second sublayer having a second composition.

13. The window of claim 11, wherein at least one of the one or more sublayers comprises a metallic material.

14. The window of claim 11, wherein at least one of the one or more sublayers comprises an undoped semiconductor or insulator material.

15. The window of claim 11, wherein at least one of the one or more sublayers comprises a semiconductor, conductor, or insulator material.

16. The window of claim 11, wherein at least one of the one or more sublayers comprises a high index material.

17. The window of claim 11, wherein at least one of the one or more sublayers comprises a low index material.

18. The window of claim 11, wherein at least one of the one or more sublayers comprises an adhesion layer.

19. The window of claim 13, wherein the metallic layer comprises aluminum, silver, gold, or copper.

20. The window of claim 14, wherein the one of more sublayers comprises a first sublayer comprising a semiconductor or conductor material and a second sublayer comprising an undoped semiconductor or insulator material.

21. The window of claim 14, wherein the semiconductor, conductor, or insulator material comprises In2O3, SnCh, ZnO, TiCh, SiCh, AI2O3, Ta20s, or ZrCh.

22. The window of claim 14, wherein the semiconductor, conductor, or insulator material comprises indium tin oxide, SnCh, ZnO, or InZnO.

23. The window of claim 20, wherein the first sublayer comprises indium tin oxide, SnO2, ZnO, or InZnO, and the second sublayer comprises In2O3, SnO2, ZnO, TiO2, SiO2, AI2O3, Ta20s, or ZrO2.

24. The window of claim 1, further comprising a mate lite, wherein lite and mate lite are part of an insulating glass unit (IGU).

25. The window of claim 1, further comprising a titanium dioxide layer.

26. The window of claim 1, further comprising a silicon dioxide layer.

27. The window of claim 1, further comprising an adhesion layer.

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