Specially Designed Triple – junction Solar Cells Based

International Journal of Electronics and Computer Science Engineering 700 Available Online at www.ijecse.org ISSN- 2277-1956

ISSN 2277-1956/V2N2-700-711

Specially Designed Triple – junction Solar Cells Based Power Generation System

Mohd Arif Ahmed

Electronics & Communication Engineering Department, R.D Engineering College Ghaziabad, Gautama Buddh Technical University Lucknow, India

1. Abstract-

This Research Report is based on the research done by the present Technical Director, John Lasich, of the Solar Systems Pvt. Ltd who was doing his research on solar photovoltaic (PV) power systems in the 1970s. Photovoltaic literally means ‘electricity-from-light’ . During his research he was basically trying to improve the efficiency of the Conventional PV Cell. While he was doing his research he came to know about the specially designed triple – junction GaInP/GaAs/Ge Solar cells which was first used by NASA on their Mars Exploration Rovers, “Spirit” and “Opportunity”. [16.1]

This Research Report contains the original Patent submitted by John Lasich which contains all the technical aspects of The Receiver Module which is basically the specially designed triple – junction GaInP/GaAs/Ge Solar cell. It also contains all the technical specifications of the CS500 dish which is the basic apparatus used in Specially Designed Triple – junction Solar Cells Based Power Generation System [16.5]

This Research Report also tells everything about the Site Selection for the implementation of the CS500 dishes i.e., for the establishments of the Solar Power Plants [16.2]

A Continues Research & Development is going on in this regard so as to improve the efficiency of the PV cell. Today’s Photovoltaic cells are currently rated at 35% efficiency with new upcoming Photovoltaic cells to be released in the coming future will approach to 60%. [16.2]

2. Acknowledgements

Any accomplishment requires the effort of many people and this work is not different.

In the completion of this Research Report I pay a special thanks to the Electronics & Communication Engineering Department of My College (R.D Engineering College) for giving me the opportunity to present my Research Report at the 1st International Conference on Advancement in Electronics & Communication Engineering ICAECE – 2013 on 22-23 Mar 2013

I also pay a special thanks to Mr. Mohit Kumar Singh and his team for helping me out in completion of this Research Report, they have corrected me whenever I was wrong or making any mistakes. Without their coordination and cooperation this Research Report will never be completed on time, I wish to express my gratitude to those who may have contributed to this work, even though anonymously.

I also want to pay thanks to my parents for cooperating me throughout the making of the Research Report and help me whenever I needed in whatever way I wanted.

3. Introduction

This Research Report is the study of the research done by the present Technical Director, John Lasich, of the Solar Systems Pvt. Ltd was doing research on solar photovoltaic (PV) power systems in the 1970s. Photovoltaic literally means ‘electricity-from-light’ . During his research he was basically trying to improve the efficiency of the Conventional PV Cell. While he was doing his research he came to know about the specially designed triple

701


ISSN 2277-1956/V2N2-700-711

– junction GaInP/GaAs/Ge Solar cells which was first used by NASA on their Mars Exploration Rovers, “Spirit” and “Opportunity”. [16.1]

After studying deeply on these specially designed triple – junction GaInP/GaAs/Ge Solar cells he came up with an idea of using these solar cells for the commercial power generation purpose but these cells are very much expensive and cannot be used as the Conventional PV Cells are used for the power production so after further studying he came up with an idea of mounting this specially designed triple – junction GaInP/GaAs/Ge Solar cell at the focus of a parabolic dish similar to our DTH receiver antennas which we generally know by the name CS500. After providing appropriate cooling to the specially designed triple – junction GaInP/GaAs/Ge Solar cell the idea was a huge success and it is fulfilling the power need of Australia in the suburbs and also cutting down the Carbon Foot Prints of Australia helping in leading towards a Greener Planet. [16.1]

Today’s Photovoltaic cells are currently rated at 35% efficiency with new upcoming Photovoltaic cells to be released in early 2011 running at around 40%. Leading cell manufacturers are already developing next-generation cells expected to operate at 45% to 50%. The technical limit of performance for volume produced multi-junction cells is anticipated to approach 60% in the future. As we strive to improve performance and cost, the long term benefit of this work to the customer will be in lower capital infrastructure cost and lower electrical energy production costs. [16.5]

On this is a new generation of solar technology,” Mr. Lasich said. “The secret is to be able to make a solar power module work about 1500 times harder than typical solar panels. If you can do this at high efficiency using low cost materials, you have the recipe for an infinite supply of clean energy at an affordable price. [16.2]

Major Differences of the Martian Surface from operating conditions of Earth orbit are

• Lower solar Intensity due to greater distance of mars from the sun

• Suspended atmospheric dust modifies the solar spectrum and reduces intensity

• Lower operating temperatures

• Deposition of dust on the arrays

The Mars Exploration Rovers, “Spirit ” and “Opportunity ”, demonstrated the first use of triple – junction GaInP/GaAs/Ge Solar cells on the surface of Mars. Well over a year after the landing of Spirit and Opportunity on the surface of Mars, the solar arrays of both rovers are continuing to perform well of the surface of Mars. Dust deposition on the solar arrays is being measured, but is not currently a limiting factor on the array performance. [16.4]

IJECSE, Volume2, Number 2

Mohd Arif Ahmed et al.

702

ISSN 2277-1956/V2N2-700-711

Convectional Photovoltaic cells use unconcentrated sunlight, or “1-sun” strength. The energy is quite diffused so large panels of photovoltaic (PV) material must be used. This requires large amount of Silicon and Expensive photovoltaic materials. As well the panels are usually mounted in a fixed position as the cost of tracking the sun for optimum output is difficult to justify. [16.2]

Solar Systems reasoned that while PV is expensive Steel and Glass are relatively cheap. Therefore, if the diffuse sunlight were concentrated on to a small area of high efficiency PV then the overall cost per unit of Electricity would be lower than unconcentrated Methods with this premise solar systems designed and defined the concept into the CS500 dish concentrator PV unit.

The CS500 has 112 curved reflecting mirrors mounted on a steel frame which tracks the sun throughout the day the combination of mirror profile mounting frame work and solar receiver are carefully designed to deliver concentrated sunlight energy to each PV module the tracking mechanism maximizes the amount of electricity produced.[16.2]

The heart of the system is an array of close packed PV cells that are located in the solar receiver suspended above the focus of the mirrors. The cells are mounted in a way that allows efficient dissipation of thermal energy as well as extraction of electricity since PV performance falls by around 1.7% for every 10 oC rise in cell temperature and the sunlight is concentrated 500x effective cooling is critical to achieve for efficient performance the module also incorporates electrical connections to deliver DC output as well as current and temperature sensors for real time monitoring.

Solar Systems module packaging technology offers the advantage of lower capital investment cost to increase production capacity compared to conventional thin film or crystalline silicon production. [16.5]

4. Cooling System The power station was originally designed to use an air fluid cooler to reject heat from the system. While this design worked inadequately, Solar Systems installed an alternative system which uses polythene pipes buried 1.5m below the earth’s surface, effectively using the ground as a heat sink. This has proved highly effective, and has reduced the cooling circuit average operating temperature by 10-150C, which boosts PV cell output and improves cell life. It has also reduced parasitic losses to further increase the overall plant efficiency.

The DC electricity from the receivers is passed through an electronic inverter that produces grid – quality AC electricity. Transformers setup up the voltage as per the requirement of the local network at the point of connection.[16.2]

The control system each dish pointing the sun monitors performance and adjusts the DC voltage to maximize the electricity outputs it also incorporates several failsafe systems to protect the CS500 from damage. Most of the solar concentrator photovoltaic power station is built from standard building materials to keep the power station costs down. Solar concentrator technology turns the sun’s energy directly into electricity. The control system incorporates a large battery bank which smoothes the output profile from the power station.

Electricity is converted to grid-quality alternating current and exported to the local electricity grid, providing extra capacity and support to the diesel generators.

The power station will use technology known as ‘Heliostat Concentrator Photovoltaic’ (HCPV). It will consist of fields of heliostats (sun-tracking mirrors) focusing sunlight on receivers. The receivers house photovoltaic (PV) modules, which consist of arrays of ultra high-efficiency solar cells that convert the sunlight directly into electricity. Photovoltaic literally means ‘electricity-from-light’. The heliostat control system, PV modules and cooling system are patented by Solar Systems. [16.2]

703


ISSN 2277-1956/V2N2-700-711

5. Heliostat

Heliostats are sun-tracking mirrors that can focus light to a point. They can be manufactured at low cost and in high volumes. They track the sun’s movement and concentrate sunlight onto high efficiency PV receivers mounted on a fixed central tower that stands approximately 40 metres high. Solar Systems uses ultra high performance solar cells developed for power generation in space. Solar Systems’ technology has the potential to supply the whole world’s power needs with less than 1% of the world’s arid land area.

Solar Systems’ technology concentrates sunlight 500 times to directly convert sunlight into power. 500 times sunlight is intense enough to melt steel. [16.2]

6. Advantages of this approach

1. Manufacturing is also much easier with the CS500 system as the area of PV material used is 1/1000 that of flat plate material

2. Unlike the traditional PV technology the CS500 is upgradeable enabling it to take advantage of future advances in PV technology the CS500 photovoltaic cells make up around 20% (by value) of the investment in the CS500 and can be easily replaced with newer higher efficiency modules this mean that the original investments can be enhanced rather than made obsolete by technology improvement in contrast to flat plate technology where the whole installation must be replaced.

3. In large scale power stations the CS500 has the advantage of being very modular enabling the power station to be distributed over a number of sites a large power station could be divided in to a number of sub stations this makes access to suitable land easier to achieve and provides additional generation redundancy to the network.

4. The CS500 has a longer effective operating life than traditional PV. Because the receiver is only a small area of PV (a 35kW CS500 dish has a PV area of 0.23m² where as 35kW of traditional flat plate would use approximately 350m²) maintenance is simple, quick and affordable. The modules include a specially designed filter that removes harmful UV radiation that reduces the operating efficiency and life of traditional PV technology. The modules are also cooled which increases their effective operating life and their efficiency.

5. The CS500 costs significantly less (per installed watt) than traditional PV technology. This is despite the fact that the CS500 is new and still near the top of its cost curve. Advances in technology, maturity and volume production will further increase the gap.

6. The CS500 produces more electricity (per installed watt) than fixed flat plate PV technology – by up to 30%. This is because it tracks the sun and operates at lower temperatures. [16.2]

Solar Systems Dense Array module utilizes high efficiency Triple Junction Solar Cells that are packed into a 36cm2 actively cooled package. The modules produce 650W of power in a footprint 340x smaller than conventional C-Silicon Solar panels and provide 500x concentration of Sunlight than conventional C-Silicon Solar panels.

The unique design with active cooling increases the reliability of the cells and produces the highest output power compared to other technologies, increasing cell life and providing more reliable operation. The Unique Dense Array configuration is modular allowing Solar Systems to design different receiver configurations and sizes for both Dish and Heliostat solar applications. [16.5]

7. CS500 Dish

Specially Designed Triple – junction Solar Cells based power generation system typically includes:

• A receiver that includes a plurality of photovoltaic cells that convert solar energy into electrical energy and an electrical circuit for transferring the electrical energy output of the photovoltaic cells

• A means of concentrating solar radiation on to the photovoltaic cells of the receiver. [16.5]



704

ISSN 2277-1956/V2N2-700-711

The Adjacent Figure 1 shows a perspective view of a preferred embodiment of a system for generating electrical power from solar radiation.

Especially Designed Triple – junction Solar Cells based electric power generating system shown in figure 1 includes a parabolic array of mirrors that reflects solar radiation that is incident on the mirrors towards a plurality of photovoltaic cells. [16.5]

The photovoltaic cells convert reflected solar radiation in to DC electrical energy.

7.1 Here in the fig.1

3 = Parabolic arrays Mirrors

7 = Receiver Module

9 = Framework holding the Mirrors

11 = Series of Arms that holds the Receiver Module

13 = Support assembly that supports the entire Dish and the Receiver Module and it also Includes a tracking system that tracks the sun

The Receiver also includes an array of 1536 closely packed rectangular photovoltaic cells which are mounted to 64 square modules. Each module includes 24 photovoltaic cells. [16.5]

The adjacent Figure 2 is a front view of the receiver of the system shown in the Figure 1 as (7) [16.5]


5 = Photovoltaic Cells

7 = Receiver Module

15 = Assembly of the receiver module

19 = Solar Flux Modifier

21 = 4 Panels that extend from the lower wall (99) and converge towards each other or we can say covers the area

23 = 64 square modules that include 1536 closely packed rectangular Photovoltaic Cells each module contain 24 Photovoltaic Cells

91 = Mirrors mounted on the inwardly facing sides of the Panels

705


ISSN 2277-1956/V2N2-700-711

99 = Lower Wall

The module shown here includes a plurality of photovoltaic cells, an electrical connection for transferring the electrical energy output of the photovoltaic cells, a coolant flow path that is in thermal contact with the photovoltaic cells so that in use coolant flowing through the flow path cools the photovoltaic cells, and a structure that supports the photovoltaic cells and defines the coolant flow path for extracting heat from the photovoltaic cells, the support structure including a coolant member formed from a thermally conductive material that at least partially defines the flow path, the support structure further including a substrate interposed between the coolant member and the photovoltaic cells, substrate including a thermally conductive layer formed from a thermally conductive material that is an electrical insulator\, and the coolant member including a base, a wall that extends upwardly from the base and contacts the substrate whereby the base, the side wall and the substrate define an enclosed coolant chamber that forms a part of the coolant flow path. [16.5]

The adjacent Figure 3 is a partially cut-away perspective view of the receiver with components removed to illustrate more clearly the coolant circuit that forms part of the receiver. [16.5]


15 = Assembly of the receiver module

17 = Parallel Coolant channels

19 = Solar Flux Modifier

21 = 4 Panels that extend from the lower wall (99) & covers the area


61 = Coolant Inlet

63 = Coolant Outlet

91 = Mirrors mounted on the inwardly facing sides of the Panels

99 = Lower Wall

The coolant flow path allows coolant to be in thermal contact with the PV cells and extract heat from the photovoltaic cells. It is preferred more particularly that in use the coolant maintains the photovoltaic cells at a temperature of no more than 40 0C.[16.5]

Coolant that is supplied form a source (not shown) follows via the inlet in to the upper horizontal post connected to the inlet and then down the vertical post connected to the upper horizontal post the coolant than flows in to the upstream lower header and, as is described above, along the channels and the coolant flow path of then modules ad in tot the downstream lower header. The coolant then flows upwards through the vertical posts that are connected to the downstream lower header and in to the upper horizontal post. The coolant is then discharged from the receiver via the outlet. [16.5]

According to the receiver’s internal arrangement there is direct thermal contact between the substrate and coolant flowing through the coolant chamber (including the channels) and between the substrate and the



706

ISSN 2277-1956/V2N2-700-711

side wall and the lands. This construction provides an effective means for transferring heat from the photovoltaic cells via the substrate to the coolant. In particular, the sidewall and the lands provide an effective, means of increasing the available contact surfaces area with the coolant to improve heat transfer to the coolant. This is an important feature given the high levels of heat transfer that are required to maintain the PV cells at temperatures below 80 0C, preferably below 60 0C, more preferably below 40 0C. [16.5]

The adjacent Figure 4 is an enlarged view of the section of Figure 3 that is described by a rectangle. [16.5]


17 = Parallel Coolant channels

39 = Base of Coolant member

45 = Coolant Inlet to Base

46 = Coolant Outlet to Base

47 = Parallel lands which are physically bonded with the substrate on which the photovoltaic (PV) cells are mounted

53 = Coolant flow channels

It is evident from the above figure that the coolant inlet, the manifold, the flow channels, the coolant outlet manifold, and the coolant outlet define the coolant flow path of each module. [16.5]

The Figure 5 is an exploded perspective view of a PV cell module that forms parts of the receiver. [16.5]




27 = Substrate on which the Photovoltaic Cells are Mounted

35 = Coolant Member it is opposite to the array of Photovoltaic Cells it is made up of copper

37 = Glass Cover of (23) 64 square modules that include 1536 closely packed rectangular PV Cells each module contain 24 Photovoltaic Cells


41 = Side wall of Coolant member (35)

707


ISSN 2277-1956/V2N2-700-711

43 = Upper Edge of the Side Wall (41) physically Bonded to the substrate (27) Substrate on which the Photovoltaic Cells are Mounted

45 = Coolant Inlet to Base

46 = Coolant Outlet to Base

47 = Parallel lands which are physically bonded with the (27) Substrate on which the Photovoltaic Cells are Mounted

49 = Coolant Inlet Manifold

51 = Coolant Outlet Manifold

53 = Coolant Flow Channels

81 = Electrical Connections

83 = Electrically Isolate the Electrical Connections [16.5]

The Figure 6 is a side elevation of the assembled PV module of Figure 5[16.5]




83 = Electrically Isolate the Electrical Connections

The Figure 7 is a section along the line of Figure 6 [16.5]




The Figure 8 is an enlarged view of the circled region in Figure 7 [16.5]



29 = Ceramic Material Centralized layer of Substrate on which the Photovoltaic Cells are Mounted

31 = Metalized layer

33 = Metalized layer



708

ISSN 2277-1956/V2N2-700-711

35 = Coolant Member it is opposite to the array of PV Cells it is made up of copper

37 = Glass Cover of 64 square modules that include 1536 closely packed rectangular PV Cells each module contain 24 PV Cells

Figure 9 is an enlarged in-depth view of the circled region in Figure 7[16.5]


27 = Substrate on which the Photovoltaic Cells are Mounted


47 = Parallel lands which are physically bonded with the (27) Substrate on which the PV Cells are Mounted

53 = Coolant Flow Channels [16.5]

8. Application : -

• Grid connected power • Water pumping & Purification Plants

• Telecommunications • Crude Oil Pumping

• Hydrogen Generation. • Remote area power supply for isolated grids

It is capable of producing 20 kW of standard 3 phase 415 volt AC power. Approximately 28 dishes are required per 1MWp generating capacity; however this number will progressively fall (with a corresponding decrease in capital costs) as new, higher efficiency cells are brought to market. [16.2]

9. The key advantages of the CS-500 dish system product are

• Highest Efficiency – by utilizing III-V triple junction technology originally developed for the space industry, currently achieving around 40% efficiency for terrestrial systems.

• High Electrical Output –High efficiency optics to maximize coupling of the concentrator optics to cells. Low loss electronics

• Dual Axis Tracking – Allows highest performance of the PV systems by tracking from sunrise to sunset.

• Safety – Built in safety features and/or shutdown in case of a system fault • Reliable Control – Field tested control software with over 10 years of development history • Modularity – Dish systems can be installed in small project i.e. < 1MW to Utility scale 100+MW

installations • Low Land Usage – Each dish is spaced to prevent shadowing and 1MW DC utilizes only 5 to 6 acres

of land, depending on local conditions • Wide Operating Temperature Range – Designed to operate over the -10°C to +60ºC ambient air

conditions • Any Terrain – Design to be used in multiple terrains from hills to flat land • Field Lifetime – Designed to operate for more than 25 years • High Wind Speed Tolerance – Design to operate in wind speeds up to 41 m/s (90mph) • Upgradeable Technology – As new cells with higher efficiency are produced, the core receiver unit

can be replaced to increase output without additional cost. [16.2]

10. Site Selection

709


ISSN 2277-1956/V2N2-700-711

There are several key criteria in selecting the appropriate location, including:

• Availability of an abundant solar resource • Access to connect to the electricity grid

• Guidance of the local government authority • Availability of appropriate land

• Suitability in terms of the interests of other stakeholders and the environment. Like any major project, the solar power station developer will have to navigate the relevant planning

and regulatory processes. [16.2]

Concentrated Photovoltaic (CPV) solar power systems work best in regions of high Direct Normal Irradiance (DNI), which is a measure of the direct sunlight that hits the ground. [16.2]

The advantage of CPV technology over conventional thin film and silicon-based PV panels is more pronounced in Areas where the DNI is highest (greater than 5 to 6 kWh/m2/day).The regions are shaded yellow on the global map shown here. The CPV solutions today provide higher energy production due to two principle differences:

• High efficiency solar cells (approximately 40% today and moving towards 50% in the next few years) • Dual Axis Tracking (significantly higher power output throughout the day compared to fixed flat

panel PV)

The Solar Systems CS500-5 Dish Product provides the greatest electrical generation capacity in the high DNI regions (yellow shaded regions). The higher electrical generation capacity of CPV systems and their low maintenance cost provide a distinct advantage to utility companies looking for high output systems with a low cost of electricity generated. [16.2]

11. About the company

The business was founded in 1990 to develop the discoveries that Technical Director, John Lasich, had made while researching solar photovoltaic (PV) power systems in the 1970s. Photovoltaic literally means ‘electricity-from-light’. Solar Systems have been developing solar concentrator PV technology for 16 years. The company achieved a world record in solar power performance in 2006. [16.2]

Solar Systems have collaborated with Spectrolab, a subsidiary of the US Company Boeing, to develop triple-junction concentrator PV cells. Solar Systems are joint owners of the new high performance solar cell technology that will be used in this project. Currently Solar Systems Ltd is engaged with the Victoria and Federal Government on the commercialization of the next generation dense array product which will be released in the middle of 2011. [16.2]



710

ISSN 2277-1956/V2N2-700-711

The company owns intellectual property including 10 patents granted and pending registered around the world, covering innovations in:

• PV modules and receivers • Optics

• Controls • Cooling

•Hydrogen production

Solar Systems’ technology is being used in four solar concentrator power PV stations in Central Australia at Hermannsburg, Yuendumu, Lajamanu and Umuwa. [16.2]

Multi-megawatt scale solar concentrator thermal technology plants have been constructed in the US, Spain and Israel. These plants use only the heat from concentrated sunlight for electricity generation. Heliostat technology is well proven in these countries. Demonstration and research heliostat systems for thermal use are also under development in NSW (New South Whales). [16.2]

Solar Systems will incorporate its high performance solar photovoltaic modules with heliostat solar concentrator technology to triple plant efficiency and significantly increase output. [16.2]

12. How green is the project?

The solar power station will generate clean electricity with zero greenhouse gas emissions – a reduction of 3,96,000 tonnes of emissions a year, according to the Australian Greenhouse Office factors for Victorian electricity supply for Victoria . [16.2]

The solar power stations were designed to provide around 30% of the daytime electrical requirements of the community. In practice, when the community requirement is low the power stations have provided up to 50% of the daytime load. It is connected to a diesel powered mini-grid that serves a number of nearby indigenous communities. [16.2]

The project will save 1, 40,000 litres of diesel & 510 tonnes of Greenhouse emissions each year [16.2]

13. Awards

Solar Systems won the 2005 Engineers Australia Engineering Excellence Award for the $7 million Indigenous solar power station project at Hermannsburg, Yuendumu and Lajamanu. [16.2]

14. Research & Development

Solar Systems Ltd is committed to long term research and development of concentrated PV Cells technology.

These areas include

• Dish concentrator research Heliostat concentrator research • Low cost manufacturing and assembly Solar cell efficiency • Dense array receivers Electrical storage

Today’s cells are currently rated at 35% efficiency with new cells due to be released in early 2011 running at around 40%. Leading cell manufacturers are already developing next-generation cells expected to operate at 45% to 50%. The technical limit of performance for volume produced multi-junction cells is anticipated to approach 60% in the future. As we strive to improve performance and cost, the long term benefit of this work to the customer will be in lower capital infrastructure cost and lower electrical energy production costs. This involved the development of a 140kW Heliostat concentration system at our Bridgewater test

Site CS500 Units Rated Output (kW)

Hermannsburg 8 192

Yuendumu 10 240

Lajamanu 12 288

Total 30 720

711


ISSN 2277-1956/V2N2-700-711

facility. This Heliostat tower is operational today and further studies on this concept will begin in mid 2011. [16.2]

A new superconducting wire can carry 40 times more electricity than a copper wire of the same size, potentially revolutionizing the power sector. High power superconductor cables take up much less space and conduct energy more efficiently, making them ideal for use in power grids. Almog and Mishael Azoulay working under Guy Deutscher, physicist at the Tel Aviv University has developed the superconducting cables, using fibers made of single sapphire crystals.

15. Control System

Solar Systems provide a proprietary software control system for management of the CS500-5 Concentrator.

Some key features include

• Drive and control systems for Azimuth and Elevation, utilize dynamic feedback tracking. • Failsafe system in the event of fault to protect the receiver. • A central control manages the site and each dish is individually controlled under direction from the

SCADA system or a local operator. [16.3]

Reference 15.1 Discovery Channel's Documentary Ecopolice 15.2 Solar Systems Ltd Official Website www.solarsystems.com.au 15.3 CS-500 Datasheet from Solar Systems Ltd Official Website www.solarsystems.com.au 15.4 NASA 's Official Website www.nasa.gov 15.5 U.S Patent By John Beavis Lasich

• Patent No US 7,076,965 B2

• Date Of Patent Jul. 18, 2006

• Application No 10/473,380

• This is national stage of international application No PCT/AU02/00402, Filed Mar. 28, 2002, and claims the benefit of Australian patent Application No. PR4038, Filed Mar. 28, 2001.

Documents

Specially Designed Triple – junction Solar Cells Based