CROSS-REFERENCE TO RELATED APPLICATIONS

An Application Data Sheet 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 Application Data Sheet is incorporated by reference herein in its entirety and for all purposes.

FIELD

Embodiments described herein generally relate to optical devices such as electrochromic devices, and methods of fabricating optical devices.

BACKGROUND

Various optically switchable devices are available for controlling tinting, reflectivity, etc. of window panes. Electrochromic devices are one example of optically switchable devices generally. 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 being manipulated 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 home, commercial, and other uses. The color, transmittance, absorbance, and/or reflectance of such windows may be changed by inducing a change in 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 it to darken; reversing the voltage causes it to lighten. This capability allows for control of the amount of light that passes through the window, and presents an enormous opportunity for electrochromic windows to be used not only for aesthetic purposes but also for energy-savings.

With energy conservation being of foremost concern in modern energy policy, it is expected that growth of the electrochromic window industry will be robust in the coming years. An important aspect of electrochromic window fabrication is coating of thin films on glass to produce an electrochromic device stack, and patterning the device stack to make it functional. Part of the patterning process includes removing portions of the device stack to reveal underlying transparent conductive oxide (TCO) in order to fabricate electrical connections, e.g. bus bars, onto the exposed lower TCO and the upper TCO, in order to deliver electricity to them and thus impart a potential across the electrochromic device stack to drive its coloring function. Selectively removing these materials to reveal the underlying TCO may be problematic, e.g., depending upon the materials that make up the electrochromic device.

SUMMARY

Embodiments described herein generally relate to optical devices such as electrochromic devices, and methods of fabricating optical devices.

Certain embodiments pertain to a method of fabricating an optical device, where the method comprises, in the following order: (a) exposing a sub-layer of the optical device to an energy source, (b) depositing one or more material layers of the optical device on the sub-layer, and (c) ablating the one or more material layers and the sub-layer with a laser to expose an underlying layer.

Certain embodiments pertain to a method of fabricating an optical device, where the method comprises: i) applying a sacrificial material layer to a portion of the area of one or more sub-layers of the optical device, ii) depositing one or more material layers of the optical device on the sacrificial material layer and the one or more sub-layers, and iii) applying a laser to the portion to ablate the optical device at least down to the sacrificial material layer.

Regarding the area of the sacrificial layer in iii), the sacrificial material layer may be completely removed from the portion of the area of the one or more sub-layers or some of the area of the sacrificial layer may remain in the area to which it was applied. Regarding depth penetration into the sacrificial layer, in certain embodiments it is desirable to remove the sacrificial layer completely so that any sub-layers are cleanly exposed, e.g. an underlying transparent conducting layer may be exposed for application of a bus bar. In other embodiments, the sacrificial layer may remain after iii) to be removed in subsequent processing steps.

Certain embodiments pertain to an optically switchable device comprising a substantially transparent substrate, a lower conductor layer disposed over the substantially transparent substrate, and a bus bar on the lower conductor layer over a portion of the area of a substrate, wherein the remainder of the area has one or more material layers including a sacrificial material layer on a sub-layer on top of the bottom conductor layer.

These and other embodiments are described in more detail below.

