초록 ▼

Process for incorporating a back surface field into a silicon solar cell by depositing a layer of aluminium on the rear surface of the cell, sintering the aluminium at a temperature between 700 and 1000째 C., exposing the cell to an atmosphere of a compound of Group V element and diffusing at a tempe

Process for incorporating a back surface field into a silicon solar cell by depositing a layer of aluminium on the rear surface of the cell, sintering the aluminium at a temperature between 700 and 1000째 C., exposing the cell to an atmosphere of a compound of Group V element and diffusing at a temperature of between 950 and 1000째C. so as to dope exposed p-type silicon surfaces with the Group V element. The step of exposing the cell to an atmosphere of a compound of a Group V element is carried separately from the step of sintering the aluminium layer, and subsequent to the step of depositing a layer of aluminium on the rear surface of the cell.

대표청구항 ▼

The invention claimed is: 1. Process for incorporating a back surface field into a silicon solar cell, which comprises the steps of: a) depositing a layer of aluminium on a rear surface of the cell; b) sintering the aluminium layer at a sintering temperature of between 700 and 1000째 C.; c) exposing

The invention claimed is: 1. Process for incorporating a back surface field into a silicon solar cell, which comprises the steps of: a) depositing a layer of aluminium on a rear surface of the cell; b) sintering the aluminium layer at a sintering temperature of between 700 and 1000째 C.; c) exposing the cell to an atmosphere of a compound of a Group V element, and diffusing at a temperature of between 950 and 1000째 C., so as to dope exposed p-type silicon surfaces with said Group V element, wherein step (c) is carried out separately from step (b) and subsequent to step (a). 2. Process according to claim 1, wherein the sintering temperature in step (b) is between 850 and 1000째 C. 3. Process according to claim 1, wherein the duration of the sintering in step (b) no more than 30 minutes. 4. Process according to claim 1, wherein the Group V element is phosphorus or arsenic. 5. Process according to claim 1, wherein the compound of the Group V element is POCl3. 6. Process according to claim 1, wherein doping of step c) is carried out at a temperature of between 960 and 1000째 C. 7. Process according to claim 1, wherein the exposed p-type silicon surfaces are in the grooves cut into the surface of the cell. 8. Process according to claim 1, wherein the silicon is monocrystalline. 9. Process according to claim 1, wherein the sintering temperature in step (b) is between 900 and 960째 C. 10. Process according to claim 1, wherein the duration of the sintering in step (b) no more than 10 minutes. 11. Process according to claim 1, wherein the aluminium is deposited to a thickness of 0.2 to 2.0 μm.