The efficiency of commercial solar cells depends not only on the design and
technology used to make the solar cell, but just as importantly on the min
ority carrier lifetime in the silicon wafer material. This paper presents a
design strategy based on matching the efficiency potential of the silicon
material to that of the silicon substrate in order to minimize the $/W cost
of a solar cell. The flexibility of the buried contact technology allows t
his design strategy to be fully utilized and a range of buried contact sola
r cell structures can be developed, each suited to a particular type of com
mercial silicon substrate. The paper demonstrates that simplified buried co
ntact solar cells are best suited to multicrystalline silicon material. Gen
eration I buried contact solar cells are optimally matched to conventional
Czochralski (CZ) substrates, and double-sided buried contact (DS BC) struct
ures will allow the thinner, higher lifetime wafers to reach their full eff
iciency potential.