Environmental Engineering Reference
In-Depth Information
Figure 7.2 Relative quantum efficiencies (left
to right) of the upper, middle, and lower light
collecting layers of the GaAs-based three-
junction tandem cell. This cell is epitaxially
constructed such that a common atomic crystal
lattice runs through the whole multilayer
system, accomplished by organometallic liquid-
phase epitaxy. The sum of the three spectra is
seen to intersect most of the sun
s spectrum.
(Spectrolab press release. http://www.
spectrolab.com/DataSheets/TerCel/tercell.
pdf)
Figure 7.3 Structure of single-crystal three-gap
GaInP/GaInAs/Ge lattice-matched cell. Cells
close to this configuration have operated at 41.6
% efficiency at 364 sun illumination.
The manufacturer Spectrolab is able to project
four- and five-junction versions of such cells
approaching 50% efficiency under concentrated
illumination [89].
