Thin film electronic devices with conductive and transparent gas and moisture permeation barriers
A thin film stack ( 100, 200 ) is provided for use in electronic devices such as photovoltaic devices. The stack ( 100, 200 ) may be integrated with a substrate ( 110 ) such as a light transmitting/transmissive layer. An electrical conductor layer ( 120, 220 ) is formed on a surface of the substrate ( 110 ) or device layer such as a transparent conducting (TC) material layer ( 120, 220 ) with pin holes or defects ( 224 ) caused by manufacturing. The stack ( 100 ) includes a thin film ( 130, 230 ) of metal that acts as a barrier for environmental contaminants ( 226, 228 ). The metal thin film ( 130, 230 ) is deposited on the conductor layer ( 120, 220 ) and formed from a self-healing metal such as a metal that forms self-terminating oxides. A permeation plug or block ( 236 ) is formed in or adjacent to the thin film ( 130, 230 ) of metal at or proximate to the pin holes ( 224 ) to block further permeation of contaminants through the pin holes ( 224 ).
1. A thin film apparatus, comprising:
a substrate comprising a light transmissive material;
a first light transmitting and electrical conductor layer formed on the substrate in a manner that produces permeation pathways that extend through the light transmitting and electrical conductor layer; and
a permeation barrier deposited with the light transmitting and electrical conductor layer, the permeation barrier comprising a plurality of oxide plugs, wherein the plurality of oxide plugs comprise metal oxide dams sealing the permeation pathways to further flow of environmental contaminants, wherein the metal oxide dams comprise a non-noble metal, and wherein that permeation barrier has a thickness of less than about 10 nanometers.
2. The device of claim 1 , further comprising a second light transmitting and electrical conductor layer, wherein the permeation barrier is interposed between the first and second light transmitting and electrical conductor layers and wherein the first and second light transmitting and electrical conductor layers both comprise a transparent conducting material.
3. The device of claim 2 , further comprising a conductivity layer positioned between the first and second light transmitting and electrical conductor layers and abutting the permeation barrier, wherein the conductivity layer is formed of a metal with an electrical conductivity greater than the permeation barrier.
4. The device of claim 1 , further comprising an additional permeation barrier formed of a layer of at least one of an organic oxide, an inorganic oxide, a nitride, or a combination thereof, wherein the additional permeation barrier is interposed between the permeation barrier and one of the other layers of the device.
5. The device of claim 1 , wherein the permeation barrier comprises one of aluminum, chromium, and titanium having a thickness of less than about 10 nanometers and wherein the light transmitting and electrical conductor layer comprises a thin film of at least one transparent conducting oxide (TCO).