Structural defects and electrical conductivity in nanocrystalline SiC : H films doped with boron and grown by photostimulated chemical-vapor deposition

Abstract

The paramagnetic DB defects and dark conductivity sigma(d) in films of nanocrystalline hydrogenated silicon doped with boron and carbon (nc-SiC:H) and grown by photostimulated chemical vapor deposition are studied. It is shown that an increase in the doping level leads to a phase transition from the crystalline structure to an amorphous structure. The electrical conductivity increases as the doping level increases and attains the value of sigma(d) = 5.5 x 10(-2) Omega(-1) cm(-1); however, the conductivity decreases once the phase transition has occurred. The concentration of DB defects decreases steadily as the doping level increases and varies from 10(19) cm(-3) (in the crystalline structure) to 9 x 10(17) cm(-3) (in the amorphous structure). (c) 2005 Pleiades Publishing, Inc.