update technology
rhombus4
Roussel sees an opportunity for GaN and SiC devices in increase cell efficiency; reduce
the power electronics market. One of the attractions of the cost of the cell; or cut
turning to these wider bandgap materials is their ability to system costs.
handle far higher current densities: silicon devices must
be operated at less than 1 A mm
-2
, while those made from Quantasol has chosen the first
GaN can be driven at 3-5 A mm
-2
. In addition, SiC and of these options, and has
GaN devices can operate ate far higher temperatures than developed a novel solar cell
their silicon brethren. technology that features
quantum well layers in the cells.
The French analyst told the attendees that the attractive The cells in a triple-junction
attributes of SiC and GaN devices have caught the eye of device are connected in series,
all the leading silicon power electronics manufacturers. and this means that the current
Market leader Infineon has pioneered the densities generated by every
commercialization of SiC Schottky diodes, and its closest cell must be matched, which
rival, Fairchild, dabbled with SiC before exiting this part of limits overall efficiency. In a
the business in 2009. The next biggest silicon power conventional device the middle
electronics manufacturer, International Rectifier, is cell produces the least current,
developing GaN products, and ST Microelectronics and and the other cells are modified
Toshiba are pursuing both types of material technologies. to reduce their current density.
Roussel expects the market for GaN and SiC devices to “What most people do to
be worth just $27 million in 2010, but will rocket to over optimize this is to make the top
$800 million by 2019. He believes that the main driver cell thin, but this is a
behind this tremendous growth is the uptake of wide compromise,” explained
bandgap diodes and transistors in hybrid electric vehicles. Shannon, who went on to reveal
Switching from devices made from silicon to those based that it is possible to increase
on SiC or GaN increases the power electronics bill, but the density in the middle cell
the far higher operating temperature of the wide bandgap from 12.5 A cm
-2
to 14 A cm
-2
by
chips allows the removal of a second water cooling adding quantum wells. Research in
system that leads to significant cost and weight savings. Motion, the
He believes that this increase in current density will make manufacturers
The wide bandgap power electronics market offers a a significant impact on the overall solar cell conversion of Blackberry
great opportunity for epiwafer providers, according to efficiencies, and backed this claim up with data from portable
Roussel. He said that many of the companies operating in recent trials that revealed an increase from 34.9 percent devices,
this arena tend to already work with external silicon to 39.6 percent, thanks to the addition of multiple employs GaAs
foundries, and they will not want to invest in their own quantum wells. MMICs made
growth facilities. IQE is yet to offer any products in this by Anadigics.
area, but there is no reason why it could not move into This efficiency is still below that produced by the leading Credit:
this sector over the coming years. developers of traditional multi-junction cells, such as Research in
Spectrolab and Fraunhofer Institute for Solar Energy Motion
A quantum leap for PV Systems (ISE), which both reported values of more than
The economic crisis took its toll on the solar market in 41 percent in 2009. And the target for Quantasol is going
2009, and according to market analyst Display Search, up, because this record tends to increase at about one
global demand experienced a year-on-year fall of 13 percent per year. However, Shannon claimed that
percent to 5.2 GW. However, a rebound is expected, with commercial device efficiencies trail the record-breaking
demand predicted to hit 26.5 GW by 2013. values by about 3 percent, and he believes that
customers will be attracted Quantasol’s launch of devices
Today systems based on concentrating photovoltaics with 41.5 percent efficiency in 2010.
(CPVs) are a negligible fraction of the current solar
market, but deployment of this technology is expected to Shannon estimates that the potential revenue for
grow strongly throughout this decade. Quantasol, a spin- Quantasol’s cells will rise over the next few years, and will
out of Imperial College London, hopes to profit from this be over $300 million by 2012. By then the efficiency of its
growth. “Our company is now ready for production and cells is expected to be over 43 percent, rising to more
commercial manufacture,” claimed Chris Shannon, who than 46 percent by 2015. This gain will result from the
has been the CEO of the company since fall 2009. introduction of quantum wells to the top cell.
If CPV technology is to enjoy significant commercial If these efficiencies can be reached, then the benefits are
success, then its power generation costs must fall. not limited to just lowering the cost of the CPV systems –
Shannon claimed that there are three ways to do this: they will also increase the addressable market, thanks to
January/February 2010
www.compoundsemiconductor.net 17
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 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87