C&I, Solar

Researchers Boost Silicon Cell Efficiency

Researchers at the Energy research Centre of the Netherlands (ECN) have developed a method to improve the solar cell efficiency for a new generation of crystalline silicon industrial solar cells. Crystalline silicon solar cells are predominantly made from p-type silicon wafers and the researchers have shown that significantly higher efficiencies can be obtained by making the solar cells from n-type silicon wafers.

A major breakthrough was a novel method for passivating the emitter of their n-type solar cells, which increases the efficiency significantly over the values obtained for p-type ones, when using cell processes of comparable cost and simplicity. For single-crystalline silicon the advantage is approximately 1%, while for multicrystalline silicon the gain depends on the quality of the silicon wafer, ECN says.

The researchers add that since the new cell process can be carried out using the same manufacturing equipment as the p-type cell process, it will allow rapid implementation, possibly even by modifying existing process lines. Together with other advantages and improvements based on this new cell process, low-cost screen printed n-type cells are potentially capable of becoming a strong new technology in the solar market. ECN intends to further develop and bring to commercialization several solar cell types based on this technology on short and medium time frames.

“We believe that n-type cell technology may offer several important advantages for commercial cell production. For example, the tolerance for some common impurities may be important for companies that want to employ new lower grades silicon feedstock. But there are also advantages inherent to the cell process, for any quality of wafer, such as the excellent blue response. We are well on our way to develop several cell processes that should be an interesting proposition to industry,” said Paul Wyers, Manager of ECN Solar Energy.