Project Title:

Passivation of InP Solar Cells

Gallia, Inc.
53 Beaver Road
Weston, MA 02193-1017

93-1		10.02   8726	A		Amount Requested $70,000

Passivation of InP Solar Cells

Abstract:

The high front surface recombination velocity (SRV) exhibited by 
indium phosphide (InP) solar cells has limited the level of 
efficiency that has been demonstrated to date.  Gallia has 
developed metal organic chemical vapor deposition (MOCVD) 
methodology to enable the growth of a previously unknown wide band 
gap (4 eV) cubic-phase of gallium sulfide (GaS), which has been 
demonstrated to passivate III-V surfaces.  Gallia's sulfide based 
coating will provide a proccessable method for the passivation of 
InP solar cell surfaces.  The project objectives include: growth of 
high purity GaS films on InP, determination of the extent of 
surface passivation, fabrication and testing of GaS passivated InP 
solar cells, determination of GaS long term stability, and 
development of alternative III-VI passivation materials.  Gallia 
will commit 900 man hours to these objectives.  It is anticipated 
that the as a result of this program Gallia will be able to 
fabricate, by MOCVD, a series of gallium chalcogenide-based 
passivation coatings for InP solar cells.  It is expected that the 
results of this project will benefit NASA in the possible 
fabrication of high efficiency InP solar cells for non-terrestrial 
applications.

Upon the completion of Phase I NASA will have the potential of a 
new product, GaS passivated InP solar cell material, and a new 
process, passivation layers by MOCVD.  The proposed project will 
have immediate and significant technological applications for the 
passivation of InP solar cell surfaces.  Furthermore, the proposed 
project will serve as a model for passivation in the more general 
area of minority carrier devices.

solar cell, Indium phosphide, Passivation, sulfide