Mitigating defects in an electrochromic device under a bus bar
Methods are provided for fabricating electrochromic devices that mitigate formation of short circuits under a top bus bar without predetermining where top bus bars will be applied on the device. Devices fabricated using such methods may be deactivated under the top bus bar, or may include active material under the top bus bar. Methods of fabricating devices with active material under a top bus bar include depositing a modified top bus bar, fabricating self-healing layers in the electrochromic device, and modifying a top transparent conductive layer of the device prior to applying bus bars.
1. A method of manufacturing an electrochromic device comprising an electrochromic stack between a first and a second transparent electrically conductive layer configured to establish an electrical potential across the electrochromic stack and thereby cause optical switching of the electrochromic device, the method of manufacturing comprising:
(a) fabricating the electrochromic stack on a glass substrate without pre-patterning in a first facility;
(b) shipping the glass substrate including the electrochromic stack to a second facility; and
(c) performing post-processing in the second facility,
further comprising (d) deactivating the electrochromic stack under at least one of one or more bus bars applied on the glass substrate during post-processing.
2. The method of claim 1 , wherein (c) comprises cutting the glass substrate to form multiple electrochromic lites.
3. The method of claim 1 , wherein the deactivating is performed either before or after applying the at least one of the one or more bus bars.
4. A method of fabricating an electrochromic device comprising an electrochromic stack between a first and a second transparent electrically conductive layer configured to establish an electrical potential across the electrochromic stack and thereby cause optical switching of the electrochromic device, the method comprising:
(a) receiving a substrate with the first transparent electrically conductive layer disposed on a surface of the substrate;
(b) fabricating the electrochromic stack on the first transparent electrically conductive layer, wherein the electrochromic stack comprises an electrochromic layer and a counter electrode layer;
(c) forming the second transparent electrically conductive layer on the electrochromic stack;
(d) deactivating a region of the electrochromic device to form a resistive material such that the electrochromic device is substantially non-functioning in the region; and
(e) forming a bus bar on a portion of the second transparent electrically conductive layer that is over first transparent electrically conductive layer,
wherein (b) and (c) are performed without electrically isolating any portion of the first transparent electrically conductive layer before forming the second transparent electrically conductive layer,
wherein the bus bar formed over the first transparent electrically conductive layer is formed over the region.
5. The method of claim 4 , wherein (d) comprises chemically reacting material in the first transparent electrically conductive layer with a reagent.
6. The method of claim 4 , wherein (d) comprises heating conductive material in the electrochromic device to form resistive material in the electrochromic device.
7. The method of claim 4 , wherein (d) device comprises treating the electrochromic device with a laser to deactivate the region.
8. The method of claim 4 , wherein the electrochromic device tints less than the bulk device or does not tint at all in the region.
9. The method of claim 4 , wherein (e) is performed prior to performing (d).
10. The method of claim 4 , further comprising cutting the substrate to form multiple electrochromic devices.