Rapid reactive transfer printing of CIGS photovoltaics
We demonstrate photovoltaic integrated circuits (PVIC) with high-quality large-grain Copper Indium Gallium
Selenide (CIGS) obtained with the unique combination of low-cost ink-based or Physical Vapor Deposition (PVD)
based nanoengineered precursor thin films and a reactive transfer printing method. Reactive transfer is a two-stage
process relying on chemical reaction between two separate precursor films to form CIGS, one deposited on the
substrate and the other on a printing plate in the first stage. In the second stage, these precursors are brought into
intimate contact and rapidly reacted under pressure in the presence of an electrostatic field while heat is applied.
The use of two independent thin films provides the benefits of independent composition and flexible deposition
technique optimization, and eliminates pre-reaction prior to the synthesis of CIGS. High quality CIGS with large
grains on the order of several microns, and of preferred crystallographic orientation, are formed in just several
minutes based on compositional and structural analysis by XRF, SIMS, SEM and XRD. Cell efficiencies of 14%
and module efficiencies of 12% have been achieved using this method. When atmospheric pressure deposition of
inks is utilized for the precursor films, the approach additionally provides further reduced capital equipment cost,
lower thermal budget, and higher throughput.
This paper was published in SPIE Proceedings Vol. 7409