About This Lesson
As the popularity of photovoltaic cells and integrated circuits increases, the need for silicon also increases. It is an inexpensive and abundant semiconductor. One of the first steps in producing silicon is carbon-thermic reduction. Silicon dioxide is melted down. Coke and other forms of carbon are then added, because the oxygen has more of an affinity to carbon instead of the silicon. A current is then run through the solution. As the impurities float to the top of the mixture, carbon monoxide vaporizes out of the solution and the metallurgical grade silicon is siphoned off the bottom.