Dear Diary,
New solar power design research conducted at the Massachusetts Institute of Technology (MIT) could lead to higher powered, more affordable solar panels.With
the help of computer simulations and various advanced
chip-manufacturing methods, a team of physicists and engineers at MIT
have discovered new ways of getting greater efficiency from photovoltaic solar cells.In
the experiment, the team applied an anti-reflective coating to the
front, and a innovative series of multi-layered reflective coatings and
a defraction grating - a closely spaced array of lines - to the back of
ultra-thin silicon films to increase the cells' power by up to 50%.With
the help of the carefully designed layers on the back of each cell,
light is bounced around longer inside the thin silicon film, allowing
it more time to China
Custom Meritor slack adjuster transfer its energy into an electric current. Without
those coatings the light would be reflected straight out of the cell.
One
of the team members, Peter Bermel, a post-doctoral researcher in MIT's
physics department explained that it is critical that any light
entering the layer should travel through a long path in the silicon.
But what they have not figured out yet is how long that path has to be
to ensure maximum absorption of electrons to produce the electric
current.The test was started by running thousands of computer
simulations, testing variations of the thickness of the silicon,
spacing of the lines, and the amount and thickness of reflective layers
on the back. These simulations were then used to optimize efficiency
and power output.According to Lionel Kimerling, the project
manager and Thomas Lord Professor of Materials Science and Engineering:
"The simulated performance was remarkably better than any other
structure, promising, for 2-micrometer-thick films, a 50 percent
efficiency increase in conversion of sunlight to electricity."Once
simulations were complete, they were confirmed by actual lab-scale
tests, where graduate student Lirong Zeng was given required to refine
the structure and make the silicon cell. As predicted, the experiment
was a success and sparked considerable industry interest.The
work done so far was just the first step toward manufacturing an
affordable, improved solar cell.
Now all that is needed is some
fine-tuning through more simulations and lab tests, and more work on
the materials and manufacturing process.According to Kimberling,
if the solar business stays strong, we can expect this new technology
to be ready within the next three years. Bermel added that, "the
potential for savings is great, since the high-quality silicon crystal
substrates used in conventional solar cells represent about half the
cost, and the thin films in this version use only about 1 percent as
much silicon."To evaluate its business potential, the project
was selected by the MIT Deshpande Center for an "i-team" study. Here it
was concluded that this thin film solar cell technology could provide
considerable benefits in both manufacturing and electricity production,
for uses ranging from remote off-grid to dedicated clean energy.While
no single project is likely to minimize the cost of solar cells, this
type of innovation takes us one step closer to making solar power design competitive with fossil fuel and nuclear grid electricity.