Design strategies for commercial solar cells using the buried contact technology

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 minority 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 this design strategy to be fully utilized and a range of buried contact solar cell structures can be developed, each suited to a particular type of commercial silicon substrate. The paper demonstrates that simplified buried contact solar cells are best suited to multicrystalline silicon material. Generation I buried contact solar cells are optimally matched to conventional Czochralski (CZ) substrates, and double-sided buried contact (DS BC) structures will allow the thinner, higher lifetime wafers to reach their full efficiency potential.