Methods of hermetically sealing photovoltaic modules
In various embodiments, photovoltaic modules are hermetically sealed by providing a first glass sheet, a photovoltaic device disposed on the first glass sheet, and a second glass sheet, a gap being defined between the first and second glass sheets, disposing a glass powder within the gap, and heating the powder to seal the glass sheets.
1. A method of hermetically sealing a photovoltaic module, the method comprising:
providing a structure comprising:
a first glass sheet,
disposed on the first glass sheet, a photovoltaic device configured to absorb at least a portion of a solar spectrum and convert the at least a portion of the solar spectrum into electricity,
a second glass sheet disposed over the photovoltaic device, the first glass sheet and the second glass sheet thereby defining a gap at least a portion of which is spanned by the photovoltaic device, and
a powder consisting essentially of glass disposed within the gap at an edge region proximate an edge of at least one of the first glass sheet or the second glass sheet, the powder being free of glass frit, frit material, organic fillers, binders, solvents, and lead; and
thereafter, heating the powder within the gap to seal the first and second glass sheets at the edge region with a layer of melted glass powder,
wherein a temperature of the photovoltaic device does not exceed 300° C. during heating of the powder.
2. The method of claim 1 , wherein the temperature of the photovoltaic device does not exceed 200° C. during heating of the powder.
3. The method of claim 1 , wherein (i) the structure comprises a conductive bus ribbon electrically coupled to the photovoltaic device and extending from the edge region, and (ii) when the edge region is sealed, the conductive bus ribbon extends from and is in direct mechanical contact with the layer of melted glass powder.
4. The method of claim 3 , wherein, at the sealed edge region, the conductive bus ribbon is disposed in direct mechanical contact with both the first and second glass sheets.
5. The method of claim 3 , wherein, at the sealed edge region, the conductive bus ribbon is disposed in direct mechanical contact with the first glass sheet and the layer of melted glass powder, but not with the second glass sheet.
6. The method of claim 3 , wherein, at the sealed edge region, the conductive bus ribbon is disposed in direct mechanical contact with the second glass sheet and the layer of melted glass powder, but not with the first glass sheet.
7. The method of claim 3 , wherein, at the sealed edge region, the conductive bus ribbon is disposed in direct mechanical contact with the layer of melted glass powder, but not with the first or second glass sheets.
8. The method of claim 1 , wherein heating the powder comprises application of laser energy to the powder.
9. The method of claim 1 , wherein the powder and the first and second glass sheets at the edge region are heated only after the powder is dispensed at the edge region.
10. The method of claim 1 , wherein a grain size of the powder ranges between approximately 0.1 μm and approximately 10 μm.
11. The method of claim 1 , wherein the powder is heated via induction heating.
12. The method of claim 1 , wherein a composition of the powder is the same as a composition of the first glass sheet and/or a composition of the second glass sheet.
13. A method of hermetically sealing a photovoltaic device, the method comprising:
providing a structure comprising:
a first glass sheet,
disposed on the first glass sheet, a photovoltaic device configured to absorb at least a portion of a solar spectrum and convert the at least a portion of the solar spectrum into electricity,
a second glass sheet disposed over the photovoltaic device, the first glass sheet and the second glass sheet thereby defining a gap at least a portion of which is spanned by the photovoltaic device, and
a powder consisting essentially of glass disposed within the gap at an edge region proximate an edge of at least one of the first glass sheet or the second glass sheet, the powder being free of glass frit, frit material, organic fillers, binders, solvents, and lead; and
thereafter, heating the powder within the gap to seal the first and second glass sheets at the edge region with a layer of melted glass powder,
wherein heating the powder comprises application of red laser energy to the powder.
14. The method of claim 8 , wherein the laser energy is applied (i) through the first glass sheet toward the powder and (ii) through the second glass sheet toward the powder.
15. The method of claim 8 , wherein the laser energy is applied (i) through the first glass sheet toward the powder or (ii) through the second glass sheet toward the powder.
16. The method of claim 8 , wherein the laser energy is pulsed during application thereof.
17. A method of hermetically sealing a photovoltaic module, the method comprising:
providing a structure comprising:
a first glass sheet,
disposed on the first glass sheet, a photovoltaic device configured to absorb at least a portion of a solar spectrum and convert the at least a portion of the solar spectrum into electricity,
a second glass sheet disposed over the photovoltaic device, the first glass sheet and the second glass sheet thereby defining a gap at least a portion of which is spanned by the photovoltaic device, and
a powder consisting essentially of glass disposed within the gap at an edge region proximate an edge of at least one of the first glass sheet or the second glass sheet, the powder being free of glass frit, frit material, organic fillers, binders, solvents, and lead;
thereafter, heating the powder within the gap to seal the first and second glass sheets at the edge region with a layer of melted glass powder; and
after the first and second glass sheets are sealed at the edge region, (i) cooling the layer of melted glass powder, and (ii) annealing the sealed photovoltaic module.
18. The method of claim 17 , wherein the sealed photovoltaic module is annealed at a temperature less than a melting point and/or a softening point of the layer of melted glass powder.