Materials and the growth of PV technology
Materials and the growth
of PV technology
David A. Preische, Indium Corporation of America, Utica, NY, USA
introduction
CIGS
The solar industry has grown
Photovoltaic technology is generally
CIGS technology offers the greatest prob-
tremendously over the last few
classified into two categories: silicon
ability for low cost PV energy generation due
years, driven by government
wafer and thin film. Silicon wafer includes
to higher cell efficiencies and total system
subsidies and concerns over
polycrystalline and single crystal silicon
costs. As a result, this technology continues
rising oil prices, increased
technologies, and these technologies have
to emerge, led by companies such as Mi-
been around for decades.
air pollution and global
asole, Showa-Shell, Honda Soltec, Wuerth,
Together they account for over 95% of
warming. This has resulted
Solyndra, Nanosolar, Q-Cells, Solibro,
solar cell production today.
SoloPower and many others.
in a significant increase in
Thin Film technologies can be broken
There are primarily four competing
the cost-per-unit of energy. down further into four categories: amor-
process technologies for development of a
The primary goal for the phous Si (a-Si), crystalline silicon on glass
CIGS solar cell: 1) sputtering using a planar
solar industry is to optimize
(CGS), cadmium telluride (CdTe) and
or rotatable target of CIG or alloy combina-
economies by adding capac-
copper-indium-gallium diselenide (CIGS).
tion, 2) printing using an alloyed powdered
ity and reducing the cost per
Thin film technologies emerging today
metallurgy with gallium applied using a
watt produced by a solar cell.
have the greater potential to offer the lowest
screen printer, 3) plating using an electro-
This goal has been difficult
cost-per-watt at the module level.
chemical plating solution and 4) evaporation
to achieve due to a shortage
or co-evaporation using a CIG elemental or
market growth
of key materials and com-
alloy composition.
The overall demand for solar over a five-year
ponents, reliability issues of
period from 2006-2010 is estimated at 52%
material concerns
existing and new materials,
CAGR, from 2,000 MWp to approximately
Indium
and various challenges in 11,000 MWp.
The most prominent discussion over the
commercializing innovative
past few years regarding material avail-
manufacturing technology.
Geographical market distribution
ability has been in relation to the metal
Germany continues to lead the way in MWp
indium. Indium usage in 2007 is estimated
fueled by government incentives, specifically
at approximately 1300 metric tonnes (mt).
a feed-in tariff (FIT) program whereby the
Approximately 75% is used within the FPD
Keywords: CIGS, Solar,
owner of a solar system is paid for electric-
industry to coat glass with indium-tin oxide
Indium, Gallium, Silicon,
ity generated by the system whether it is
for LCD and plasma TVs, laptop computers,
Tabbing Ribbon
consumed or fed back to the grid. This con-
monitors, cell phones, etc. The remaining
trasts with a net-metering incentive, which
25% is used in manufacturing processes for
measures the difference between the total
alkaline batteries, CIGS solar cells, semicon-
This paper was originally presented
amount of electricity generated and what is
ductors, thermal-interface materials, and for
at SMTAI 2008.
actually consumed.
a variety of niche soldering applications.
Indium, a by-product of zinc, is 3x more
abundant than silver. More than 50% of
!
!
!
Figure 1. PV demand by technology. Figure 2. Global PV demand. Figure 3. CIGS technology growth.
6 – Global Solar Technology – November/December 2008 www.globalsolartechnology.com
Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48