Pretreatment of transparent conductive oxide (TCO) thin films for improved electrical contact
Certain embodiments relate to optical devices and methods of fabricating optical devices that pre-treat a sub-layer to enable selective removal of the pre-treated sub-layer and overlying layers. Other embodiments pertain to methods of fabricating an optical device that apply a sacrificial material layer.
1. An optical device comprising:
a substantially transparent substrate;
a first transparent conductive oxide (TCO) layer disposed on the substantially transparent substrate;
a bus bar disposed on the first TCO layer in a bus bar pad expose area of the substantially transparent substrate;
wherein a remaining area of the substantially transparent substrate includes a stack of one or more material layers comprising a titanium dioxide (TiO 2 ) layer disposed on the first TCO layer; and
wherein the remaining area of the substantially transparent substrate also includes a second TCO layer disposed on top of the stack of one or more material layers.
2. The optical device of claim 1 , wherein the optical device is an electrochromic device.
3. The optical device of claim 1 , wherein the stack of one or more material layers further comprises a WO 3 electrochromic layer and a nickel-based counter electrode layer.
4. The optical device of claim 1 , wherein the stack of one or more material layers comprises a tungsten oxide (WO 3 ) electrochromic layer and a nickel-based counter electrode layer.
5. The optical device of claim 1 , wherein the stack of one or more material layers comprises a counter electrode layer comprising NiWO or NiTaO.
6. The optical device of claim 1 , wherein the first TCO layer and/or the second TCO layer comprises tin oxide.
7. The optical device of claim 1 , wherein the stack is an electrochromic device stack.
8. The optical device of claim 1 , wherein the TiO 2 layer has higher absorptive properties relative to the first TCO layer.
9. The optical device of claim 1 , wherein the first TCO layer comprises SnO 2 .