Silicon exists in nature as three stable, non-radioactive, isotopes: Si-28 (92 per cent), Si-29 (five per cent) and Si-30 (three per cent). By purification at the sub-atomic level, it is possible to remove essentially all of the Si-29 and Si-30 leaving isotopically pure Si-28, which has a more perfect crystal structure.
This more perfect crystal structure exhibits reduced phonon-phonon and phonon-electron interactions which increases certain transport properties, such as thermal conductivity. It has been demonstrated in the laboratory that isotopically pure Si-28 has 60 per cent better room temperature thermal conductivity than natural silicon with its three isotopes.
Improvements in other physical and electrical properties are also theoretically possible. ®