Why Silicon is preferred in semiconductor?
Although both silicon & germanium are used in semiconductor devices. The present day trend is to use silicon.The main reason for this are: (1) Smaller ICBO : Silicon have much smaller collector cut off current than germanium. So at room temperature, silicon crystal has fewer free electrons than germanium crystal. (2) Smaller variation of ICBO with temperature : The variation of collector cut off current with temperature is less in silicon compared to germanium. (3) Greater working temperature : The structure of germanium crystals will be destroyed at higher temperature however, silicon crystal are not easily damaged by excess heat. (4) Higher PIV rating: Peak inverse voltage rating of silicon diode are greater than germanium diode. (5) Less expensive: Silicon is less expensive due to the greater abundance of element.The major raw material for silicon wafer fabrication is sand & there is lots of sand available...