Lift-off layer for separation and disposal of energy conversion devices
View Patent ↗Separation layers, usable in devices for converting radiation energy to electrical energy, allow at least some of the components of the devices to be separated from one another for disposal thereof. A separation layer may be interposed between and bonded to adjoining layers, and when acted upon by application of an external source, may be degraded to release the layers from one another. Once released, the layers may be disposed of more efficiently and economically, including proper disposal of hazardous waste, and recycling of materials which may be re-usable.
1. A method for disposing of at least a portion of a device for converting radiation into electrical energy, the device having a substrate, a conversion layer configured to convert radiation into electrical energy, and a layer of at least one metal disposed between and bonded to the substrate and the conversion layer, wherein the at least one metal substantially maintains the electrical, chemical and physical properties of the conversion layer when bonded to the conversion layer, the method comprising:
exposing the device to one of at least one acid or at least one base to dissolve the at least one metal for separating the conversion layer from the substrate; and
separately disposing of at least a portion of each of the substrate and the conversion layer,
wherein exposing the device and separately disposing of at least a portion of each of the substrate and the conversion layer occur at the end of a service life of the device.
2. The method of claim 1 , further comprising:
extracting at least a portion of at least one additional component from at least one of the substrate and the conversion layer; and
separately disposing of at least a portion of the extracted component and at least a portion of the at least one of the substrate and the conversion layer.
3. The method of claim 1 , wherein exposing the device comprises exposing the device to one of the at least one acid or the at least one base to dissolve the at least one metal, wherein the at least one metal comprises one or more of the following: cobalt, lead, platinum, gold, silver, copper, chromium, titanium, zinc, magnesium, scandium, vanadium, manganese, iron, nickel, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, cadmium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, mercury, rutherfordium, dubnium, seaborgium, bohrium, hassium, meitnerium, ununnilium, unununium, and ununbium.
4. The method of claim 1 , wherein exposing the device comprises:
processing the device to break down the device into pieces having a size of less than about 1 cm 2 prior to separating of the conversion layer from the substrate;
mixing the pieces with a solution of the one of at least one acid or at least one base to dissolve the metal to release the conversion layer from the substrate, resulting in a mixture of pieces of the conversion layer and pieces of the substrate in solution;
separating the mixture of pieces of the conversion layer and pieces of the substrate from the solution;
separating the pieces of the conversion layer from the pieces of the substrate; and
wherein the separately disposing comprises separately disposing of the pieces of the conversion layer and the pieces of the substrate.
5. The method of claim 4 , wherein:
the processing comprises processing the device to break down the device into pieces having a size of less than about 1 cm 2 by means of at least one of grinding, milling, crushing, shredding, tearing and chopping;
the separating the mixture of pieces of the conversion layer and pieces of the substrate from the solution comprises one or more of: decanting the solution from the pieces; filtering the pieces from the solution, density separation and physical separation;
the separating the pieces of the conversion layer from the pieces of the substrate comprises one or more of: physical separation, density separation and centrifuging the mixture of pieces of the conversion layer and pieces of the substrate; and
the separately disposing comprises recycling at least a portion of the pieces of the conversion layer and at least a portion of the pieces of the substrate.
6. The method of claim 1 , wherein the disposing comprises disposing of the at least a portion of the device for converting radiation into electrical energy, wherein the radiation comprises radiation having a wavelength between about 10 −2 m to about 10 −12 m, and the device comprises one of: a rectenna, a nantenna, a photovoltaic cell, and a radiation harvester.
7. The method of claim 1 , wherein the disposing comprises disposing of the at least a portion of the device for converting radiation into electrical energy, wherein the device comprises one of:
a CIGS photovoltaic device and the conversion layer comprises a CIGS layer; and
a CIS photovoltaic device and the conversion layer comprises a CIS layer.
8. The method of claim 5 , wherein recycling the at least a portion of the pieces of the conversion layer comprises extracting molybdenum from the at least a portion of the pieces of the conversion layer.
9. The method of claim 8 , wherein extracting the molybdenum comprises:
heating the pieces of the conversion layer to a temperature sufficient to oxidize the molybdenum to form molybdenum trioxide gas; and
isolating and converting molybdenum trioxide gas to solid molybdenum.
10. The method of claim 9 , wherein converting molybdenum trioxide gas to solid molybdenum comprises:
reducing the molybdenum trioxide with a reduction agent to form solid molybdenum;
reducing the molybdenum trioxide with hydrogen to form solid molybdenum;
dissolving the molybdenum trioxide with ammonia to form molybdates; and
reducing of the molybdenum trioxide with iron to form ferromolybdenum.