Recent improvements of crystalline silicon solar cells in Japan

Fundamental research on the recombination of minority carriers at Si/SiO₂ interfaces and grain boundaries is discussed. Qualities of feedstock and cast ingots are improved. Large-area cell efficiencies using CZ single and cast polycrystalline substrates are improved to 19.5 and 16.4%. The high values are achieved by using low-cost cell fabrication processes. Fundamental and preliminary research into the realization of very-high-efficiency solar cells has been initiated