NJIT Physics Department Seminar


Concentrator Photovoltiacs for Electricity Production




*2/19/08, Tuesday

*Time: 2:30-3:30 pm

Room: 373 Tiernan


Dr. Daniel Friedman

Concentrator Photovoltiacs Group Manager
US DOE National Renewable Energy Laboratory

(Materials / Device Physics, Host: Tyson)



This talk discusses the challenge of bringing solar electricity
(photovoltaics, or "PV" for short) to the point of supplying a
significant fraction of the demand for electrical power in the US. A
key step to addressing this challenge involves identifying niches in
the existing power market where PV is economically viable at its
present cost. In parallel, development of PV technology must bring
its costs down to be competitive for large, utility-scale
application. One promising approach to lowering the cost of PV is to
use large, inexpensive optics to gather sunlight and focus
("concentrate") it down onto solar cells, thereby reducing the
amount of the costly solar cell which is needed. This talk addresses
both these steps, with emphasis on the extremely high-efficiency
solar cells which are driving concentrator PV technology, and gives
examples of several types of concentrator PV which are being
developed to supply the growing market for PV power.

Brief Biography
Dr. Friedman joined the National Renewable  Energy Laboratory in
1990, working in the III-VMaterials and Devices group. His interests
have  been in the development of next-generation
multijunction high-efficiency solar cells for concentrator systems.
One of his early focuses after joining the group was to adapt
the  GaInP/GaAs multijunction cell technology for  concentrator
operation, developing the first monolithic two-terminal solar cell to
have a verified efficiency greater than 30%. More recently, he has
studied novel semiconductor materials for photovoltaics, such as
GaInNAs for potential application in a 1-eV-bandgap device on
conventional GaAs or Ge substrates, as well as developing concepts
for junctions suitable for fabrication on Si. His current work
centers on development of future generations of lattice-mismatched
multijunction cell structures for ultrahigh-efficiency operation
under  concentration. Dr. Friedman has published more than 50 papers
and two book chapters. He is currently the manager of
NREL's  Concentrating Photovoltaics Group.