Batteries: thermoelectric and photoelectric – Photoelectric – Cells
Patent
1997-05-29
1999-11-23
Diamond, Alan
Batteries: thermoelectric and photoelectric
Photoelectric
Cells
136258, 136260, 136261, 136262, 136264, 257461, 257463, 257464, 257106, 257 61, 438 95, 438 96, 438 97, 438 98, H01L 3106, H01L 27142, H01L 2362, H01L 3118
Patent
active
059904151
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This application is a 371 of PCT/AU95/00829 filed Dec. 8, 1995.
The present invention relates generally to the field of solar cell technology and in particular the invention relates to the manufacture of a solar cell with an integrated bypass diode.
The invention provides a new method for providing protection during operation and for potentially increasing manufacturing yield of these devices by the incorporation of integral bypass diodes into a multilayer structure. The features of the multilayer structure make the incorporation of these diodes feasible in a way which would be difficult with conventional devices.
BACKGROUND OF THE INVENTION
The solar cells with integrated bypass diodes are of particular interest in the manufacture of multilayer solar cell which are the subject of earlier commonly assigned Australian Patent Application No PM4834 entitled "Multiple Layer Thin Film Solar Cells" which is incorporated herein by reference.
In the prior art a bypass diode is a diode connected in reverse polarity to the diode which constitutes the solar cell. In normal practice, these bypass diodes are discrete diodes which are physically connected across individual cells or groups of cells by techniques such as soldering. In normal operation, these bypass diodes are reverse biased and do not interfere with cell operation. However, when cells have lower current output than others in the system, due to effects such as shadowing or cell damage, these diodes provide a low resistance path around the low output cells. This serves two functions. The first is to prevent excessive reverse voltage building across low output cells which can lead to cell destruction by overheating. The second role is to control the disproportionate loss of power output that such a shaded or damaged cell could introduce into the system of interconnected cells. The purpose and function of bypass diodes are well understood and widely discussed in standard texts such as Martin A. Green, "SOLAR CELLS: Operating Principles, Technology and System Applications", (Prentice-Hall, New Jersey, 1982) and S. R. Wenham, M. A. Green and M. Watt, "Applied Photovoltaics", (Bridge Printery, Sydney, 1994). Prior art integral bypass diodes serve a similar function although in general, due to their incorporation directly into the solar cell structure, lead to a reduction in the active volume of the cell with a corresponding reduction in performance even when the bypass diode is reverse biased.
Although bypass diodes are generally incorporated to provide protection and to decrease power losses during operation in the field, a new and advantageous application of the present invention is to use such diodes to maintain high production yields of modules of interconnected cells by providing automatic bypass of damaged or poorly performing cells within the module. One strategy, well suited to module fabrication where there is no prior testing of individual cells, is to include a small number of additional cells so that a guaranteed minimum output will be achieved even in the event of a small number of cell failures.
SUMMARY OF THE INVENTION
According to a first aspect, the present invention provides a solar cell including a plurality of doped semiconductor regions defining a rectifying junction of a photovoltaic cell, at least a portion of the junction forming a bypass diode having a reverse bias characteristic whereby conduction occurs under predetermined reverse bias conditions.
According to a second aspect the present invention provides a solar cell including a plurality of doped semiconductor regions defining a first rectifying junction of a photovoltaic cell and a second rectifying junction effectively connected in parallel to and with the same polarity as the first rectifying junction, at least a portion of the second junction forming a bypass diode having a reverse bias characteristic whereby conduction occurs under predetermined reverse bias voltage conditions.
The junction portion forming the bypass diode is preferably formed by p
REFERENCES:
patent: H667 (1989-09-01), Bedair et al.
patent: 4323719 (1982-04-01), Green
patent: 4385198 (1983-05-01), Rahilly
patent: 4933022 (1990-06-01), Swanson
patent: 5136353 (1992-08-01), Pankove et al.
patent: 5248346 (1993-09-01), Fraas et al.
patent: 5389158 (1995-02-01), Fraas et al.
patent: 5461002 (1995-10-01), Safir
patent: 5580395 (1996-12-01), Yoshioka et al.
patent: 5609694 (1997-03-01), Asai
patent: 5616185 (1997-04-01), Kukulka
patent: 5665175 (1997-09-01), Safir
patent: 5797998 (1998-08-01), Wenham et al.
Sproul, A. B. et al.: "Crystalline and polycrystalline silicon tandem junction solar cells: theoretical advantages" Solar Cells, Jul. 1986, Switzerland, vol. 18, NR. 1, pp. 31-40, ISSN 0379-6787 XP-002059152.
Martin A. Green: "Solar Cells--Operating Principles, Technology and System Applications", Feb. 1992, Chap. 11, pp. 212-219.
Green Martin Andrew
Wenham Stuart Ross
Diamond Alan
Pacific Solar Pty Ltd
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