High-Efficiency P-Type Commercial Silicon
Solar Cell
The Double-sided Buried Contact (DSBC) solar
cell incorporates a high-efficiency rear surface design in the
commercially successful Laser-groove or Buried-contact cell design
(shown below). The rear grid provides localised contacts to the
base and allows the majority of the rear surface to be passivated,
for example either by a dielectric coating or in conjunction with
a doped layer. If successful, this structure will allow increased
open-circuit voltage in thin-wafer solar cells. Another advantage
of a rear grid contact is that it allows a light trapping scheme
to be implemented independent of the electrical requirements of
the rear contact allowing high short-circuit current to be maintained.
Schematic of the DSBC solar cell.
DSBC solar cells typically exhibit good open-circuit
voltage and light-generated current, but suffer from reduced fill
factor. Detailed modelling of the local ideality factor curve as
a function of voltage (m-V) and current voltage curves (I-V, or
J-V if current density) have demonstrated a possible link between
these low fill factors and assymetric Shockley-Read-Hall
(SRH) recombination in the bulk region, the cause of which
is currently under investigation[1].
Other research efforts include identifying the mechanism
lowering the fill factor of the DSBC solar cell and identifying
the stress mechanisms that occur during the growth of silicon on
textured wafers(see 2003 Annual Report
Section 5.3.1).
[1] P.J. Cousins, C.B. Honsberg, A.B. Sproul and
J.E. Cotter, “The effect of SRH recombination on the fill
factor of double sided buried contact solar cells”, 40th
ANZSES Conference, Newcastle, 2002.
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