Method and system for large scale manufacture of thin film photovoltaic devices using single-chamber configuration
View Patent ↗A system for large scale manufacture of thin film photovoltaic cells. The system includes a chamber comprising a plurality of compartments in a common vacuum ambient therein. Additionally, the system includes one or more shutter screens removably separating each of the plurality of compartments. The system further includes one or more transfer tools configured to transfer a substrate from one compartment to another without breaking the common vacuum ambient. The substrate is optically transparent and is characterized by a lateral dimension of about 1 meter or greater for a solar module. Embodiments of the invention provide that at least some of the plurality of compartments are configured to subject the substrate to one or more thin film processes to form a Cu-rich Cu—In composite material overlying the substrate and at least one of the plurality of compartments is configured to subject the Cu-rich Cu—In composite material to a thermal process to form a chalcogenide structured material.
1. A system for large scale manufacture of thin film photovoltaic cells, the system comprising:
a chamber comprising a plurality of compartments in a common vacuum ambient therein;
one or more shutter screens removably separating each of the plurality of compartments;
one or more transfer tools configured to transfer a substrate from one compartment to another without breaking the common vacuum ambient, the substrate being optically transparent and being characterized by a lateral dimension of about 1 meter or greater for a solar module;
wherein at least some of the plurality of compartments are configured to subject the substrate to one or more thin film processes to form a Cu-rich Cu—In composite material overlying the substrate and at least one of the plurality of compartments is configured to subject the Cu-rich Cu—In composite material to a thermal process to form a chalcogenide structured material.
2. The system of claim 1 wherein the substrate comprises a soda lime glass, a quartz, a fused silica, or a plastic, or other composite materials.
3. The system of claim 1 wherein the plurality of compartments includes a first compartment for forming an electrode layer overlying the substrate in a vacuum ambient with a pressure of about 6.2 mTorr or lower.
4. The system of claim 3 wherein the first compartment comprises one or more sputtering targets disposed in series for depositing the electrode layer with a total thickness ranging from 300 nm to 400 nm and characterized by resistivity of about 100 ohm-cm to 10 ohm-cm and less.
5. The system of claim 1 wherein the plurality of compartments includes a second compartment for forming a copper-bearing layer, the second compartment being maintained at the substantially same vacuum ambient of the first compartment.
6. The system of claim 5 wherein the second compartment comprises a sputtering target made of Cu-bearing material for depositing the copper-bearing layer using a DC magnetron sputtering technique.
7. The system of claim 6 wherein the Cu-bearing material comprises pure copper or copper-gallium alloy.
8. The system of claim 5 wherein the plurality of compartments includes a third compartment for forming an indium layer overlying the copper-bearing layer to form the Cu-rich copper-indium composite material with copper to indium atomic ratio greater than 1.2.
9. The system of claim 1 wherein the at least one of the plurality of compartments configured to subject the Cu-rich Cu—In composite material to a thermal process comprises a plurality of nozzles for supplying gas phase sulfur bearing species and one or more heaters for heating the compartment from room temperature to about 500 degrees Celsius.
10. The system of claim 1 wherein the chalcogenide structured material comprises a photon absorber of a thin film photovoltaic cell.