Amorphous diamond-Si semiconductor heterojunctions

Abstract
Tetrahedrally co-ordinated amorphous carbon (amorphous diamond) deposited from the plasma stream of a vacuum arc on a graphite cathode is demonstrated as having semiconductor properties. The material is shown to form a heterojunction with both p- and n-type Si. A band gap of 2.9 eV is proposed for the a-diamond, based on the observed I-V characteristics of the heterojunction diodes. The material has a measured electrical breakdown strength of 109 V/m, which is comparable to that of high quality insulators such as SiO2 and Si3N4. Gas phase doping using B2H6, PH3, and N2 has been attempted.