Environmental Engineering Reference
In-Depth Information
creating beneficial or detrimental effects. The incorporation of
hydroxides in semiconductors can be a major issue when aqueous
solutions are used. Due to the above reasons, one may not be
able to grow some materials using aqueous media, but a large
number of semiconductors [10] have been successfully grown to
date using this method. Hydroxide incorporation can be avoided by
usingnon-aqueoussolventslikeDMSO.However,overthepastthree
decades, the lack of close collaboration between the two disciplines
chemistry and physics has been a major barrier for rapid progress
in electronic device development based on the electrodeposition of
semiconductors.
One other disadvantage of electrodeposition is that the sub-
strates are limited only to conducting surfaces. Materials cannot
be deposited on insulating surfaces without having electrical
conduction.Anothercomplicationisthattheconductinglayeronthe
substrate may dissolve in the acidic or alkaline electrolyte solutions
used during the electrodeposition of the material.
3.6 Current Work and Future Prospects
The use of electrodeposition as a growth technique for solar
energy materials and nanomaterials is getting more popular in the
research community. The experimental results currently reported
are impressive, and this simple technique allows the simultaneous
variation of the bandgap of CuInGaSe
2
between 1.10 eV and 2.20 eV
and the electrical conduction type from p
+
to n
+
by changing the
depositionvoltage.Inaddition,thismethodiscapableoffabricating
any number of electronic material layers necessary for solar cell
devices. If these capabilities are used in the manufacture of large-
area solar panels, the production cost could be reduced by a
considerable factor in the future.
Making use of electrodeposited CdTe layers, small-scale device
e
ciencies of 18% for CdS/CdTe solar cells have been reported
[23]. However, the reproducibility of these high-e
ciency devices
remains a real challenge for PV researchers. A deeper understand-
ing of the electrodeposition process, material properties, device
structures, and the underlying physics principles will help in
