Czochralski, Jan
Jan Czochralski (1885-1953), a Polish chemical engineer who made seminal contributions to the commercialization of photovoltaic cells. In 1916, Czochralski developed a technique to obtain single crystals of a semiconductor from methods used originally to measure crystallization rates of metals. It is said that he discovered this serendipitously after accidentally dipping his quill into a tub of molten metal instead of an inkpot. This method, now known as the Czochralski method, was not widely used until after World War II, when the demand for semiconductor electronic materials increased. In 1954, Bell Laboratories produced the first photovoltaic cell using the Czochralski method. The process requires placing a single rotating crystal silicon seed onto a rod, which is then immersed in molten silicon. Slowly extracting the silicon seed from the silicon bath produces a monocrystalline silicon cylindrical ingot with practically no defects and good conversion efficiency. The Czochralski method remains expensive, forcing many manufacturers of photovoltaic cells to produce multicrystalline ingots, which have lower conversion efficiencies. Czochralski also made the first published attempt to develop a microscopic theory of recrystalization.
Further Reading
- Cemat Silicon SA. Professor Jan Czochralski, inventor of Czochralski method.
- U.S. Department of Energy, Energy Efficiency and Renewable Energy. The History of Solar (PDF).