ISSN:
1089-7550
Quelle:
AIP Digital Archive
Thema:
Physik
Notizen:
Low-temperature optical absorption experiments have been performed on a variety of n-type, p-type, and high-resistivity silicon carbide samples, including the polytypes: 4H, 6H, and 15R. These experiments reveal a set of absorption band close to the band edge with a fine structure depending upon the polytype. Each sample exhibits a spectrum with the number of lines corresponding to the number of inequivalent substitutional lattice sites contained in the polytype. A correlation of these lines with the neutral vanadium 2E→2T2 intracenter transition indicates that the initial state for the near-band-gap absorption lines is the 2E state of the 3d1 configuration of vanadium. The near-band-edge absorption lines were interpreted as due to an exciton bound to a vanadium donor with an electron occupying an atomic-like d state. The position of the vanadium acceptor level was estimated to be, at most, 250 meV from the conduction band for the cubic site in 6H SiC. © 1995 American Institute of Physics.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.360004
