Manufacturing method of multi-junction PV modules
A photovoltaic device is provided which includes a plurality of junction layers. Each junction layer includes a plurality of photovoltaic cells electrically connected to one another. At least one of the junction layers is at least in part optically transmissive. The junction layers are arranged in a stack on top of each other.
1. A method of producing a photovoltaic device, comprising
forming a plurality of junction layers on a plurality of substrates, each of said plurality of junction layers comprising a plurality of photovoltaic cells electrically connected to one another, at least one of said of said plurality of junction layers being at least in part optically transmissive; and
stacking the plurality of junction layers on top of each other such that at least two of said substrates being separated from one another by a junction layer.
2. The method of claim 1 , wherein further comprising forming the plurality of junction layers so that each of said junction layers comprises at least one pair of electrical terminals for receiving photogenerated current.
3. The method of claim 1 , further comprising laminating the junction layers to one other.
4. The method of claim 1 , further comprising electrically insulating the junction layers from each other.
5. The method of claim 1 , wherein said plurality of junction layers comprises at least first and second junction layers, and further comprising forming the first junction layer so that it is configured to absorb a first portion of incident light energy and transmit a second portion of the incident light energy to the second junction layer, and forming the second junction layer so that it is configured to absorb at least a portion of the second incident light energy.
6. The method of claim 5 , wherein said first junction layer comprises photovoltaic cells with a characteristic bandgap that is larger than that of cells in said second junction layer.
7. The method of claim 1 , wherein a number of said photovoltaic cells in at least two of the junction layers are chosen so that their respective output voltages are about equal.
8. The method of claim 1 , wherein a number of said photovoltaic cells in at least two of the junction layers are chosen so that their respective output currents are about equal.
9. The method of claim 1 , further comprising electrically connecting at least two of the junction layers in parallel.
10. The method of claim 1 , further comprising electrically connecting at least two of the junction layers in series.
11. The method of claim 1 , further comprising forming the photovoltaic cells in at least one of the junction layers from a CIGS alloy.
12. The method of claim 1 , further comprising forming the photovoltaic cells in at least one of the junction layers from a CdTe alloy.
13. The method of claim 1 , further comprising electrically connecting the photovoltaic cells in each junction layer to one another in series.
14. The method of claim 1 , further comprising forming an insulating layer between two adjacent ones of the junction layers stacked on top of one another.
15. The method claim 1 , further comprising forming the photovoltaic cells in a first of the junction layers with an output polarity that is reversed from an output polarity in a second of the junction layers adjacent to the first junction layer.
16. The method claim 1 , further comprising forming at least one bypass diode in at least one of the junction layers.
17. The method of claim 1 , further comprising:
electrically connecting the photovoltaic cells in first and second ones of the plurality of junction layers in parallel with one another; and
forming at least one blocking diode in series with the photovoltaic cells in each of the first and second ones of the plurality of junction layers.
18. The method of claim 1 , further comprising:
electrically connecting the photovoltaic cells in first and second ones of the plurality of junction layers in series with one another; and
forming at least one bypass diode in parallel with the photovoltaic cells in each of the first and second ones of the plurality of junction layers.
19. The method of claim 1 , wherein at least one of the substrates is non-planar.
20. The method of claim 1 , wherein the at least a first pair of the plurality of junction layers are connected to one another in series and at least a second pair of the plurality of junction layers are connected to one another in parallel.