chemistry

[mohanbharathrao]

can sio2(sand) be melted and doped with phosphorus by czochralski process so that it can conduct electricity?

[rmarz]

mohanbharathrao - The Czochralski process will grow single crystal material from a 'melt' of relatively pure silicon (not Sio2), and within the process dopants can be added which will become part of the crystal lattice structure. The resulting 'doped' silicon will be conductive dependent on the dopant material and concentration. It is this ability to transform elemental silicon to single crystal silicon that, dependent on the dopant used, will form p-type or n-type silicon materials, the heart of semiconductor devices. Your question is whether SiO2, (silicon dioxide or sand), can be melted and with a dopant, be transformed into conductive single crystal material using a Czochralski furnace. The simple answer to that is no. While you can melt the sand and add a dopant, it will not form, or grow, a crystal lattice upon cooling. What you will have is a simple glass with a dopant material that will be a compound. Many years ago an innovative inventor, Stanford Ovshinsky, pioneered the field of 'amorphous silicon' that was, in many ways ahead of it's time. While never becoming a commercial success, the material theories have been proven many years later within the semiconductor industry. Some of the early experimentation looked into highly doped materials more like glass than elemental silicon. You might find some interesting reading with some research.

Rick Marz