Complete Report - University of New South Wales

New Semiconductor Finger Technology
The new semiconductor fi nger technology developed jointly between UNSW and Suntech-
Power for screen-printed solar cells has been successfully implemented at the pilot production
level using the same materials and equipment as for standard screen-printed solar cells. The
10% performance gain is achieved without any increase in cell manufacturing cost, with the
new jointly owned technology expected to be in large scale production in 2006. Based on
pilot production experience, cell effi ciencies for the new technology in large scale production
are expected to average about 18%. A particular strength of this new solar cell design is the
ability to achieve extremely good spectral response, particularly for short wavelengths of light,
compared to most commercial cell technologies. This new cell design appears to overcome
the fundamental weaknesses of conventional screen-printed solar cells associated with the
heavily diffused emitter, but while retaining the many benefi ts of screen-printing technology.
This work won “The Best Oral Presentation” award for its area at the International PVSEC-15
Conference in Shanghai in October 2005 and has been selected as an invited paper as part
of the plenary session at the World Conference in Hawaii in May 2006.
Image of a screen-printed
metal line (foreground) in
excellent contact with a
heavily phosphorus-diffused
laser groove running
perpendicular to the metal
line. The region covered with
tiny pyramids is lightly diffused
with phophorus.
Thin-Film Silicon
4
Good progress has been made with the Thin-Film Group’s solar cell technologies EVA, ALICIA
and ALICE. A milestone achieved in 2005 was the realisation of the Group’s fi rst poly-Si
thin-fi lm solar cells on glass with voltages of over 500 mV. The best cell has a voltage of
517 mV obtained with the EVA structure which, to our knowledge, is a new world record
for homojunction poly-Si thin-fi lm solar cells on glass. Another important milestone was
the achievement of an internal quantum effi ciency of over 70%, obtained using the ALICIA
structure. These advances benefi ted signifi cantly from an improved hydrogenator that became
available in 2005 in the Centre’s research facility at Bay Street, Botany. Good progress was
also made with optimising and upscaling of the Group’s AIT glass texturing method and its
AIC seed layer process. As a result of this work, AIT-textured glass sheets and AIC-seeded
glass sheets with a size of 10 x 10 cm 2 are now routinely produced by the Group. Progress
with cell metallisation has improved the effi ciency of ALICIA cells to 3%. The Group was again
active in generating intellectual property, with the fi ling of a provisional Australian patent on
an interdigitated thin-fi lm cell metallisation method (“SAMPL”) and the entering of the national
phase for two recent PCT patent applications. Furthermore, the Group has published one
book chapter, eleven journal papers, and twenty one conference papers. Fifteen of these
papers were presented as talks at international conferences, including four invited talks by
the Group’s leader, Armin Aberle. The Group’s thin-fi lm solar cell technologies are attracting
a signifi cant amount of interest from the solar industry and the venture capital sector. In
response to this interest, the Group has created a commercialisation roadmap involving a
business plan proposal and layouts of a pilot line and a fi rst factory. UNSW’s commercial arm,
NewSouth Innovations Ltd, has entered negotiations with several interested parties.