Dynamic impurities in ultrapure semiconductors
Abstract
Theoretical and experimental results are presented which shed light on a series of unusual shallow level impurities in ultrapure germanium. These impurities, both donors and acceptors, (1) show hydrogenic spectra with signatures identical to all other shallow impurities; (2) exhibit unusual dependence in their spectra to applied uniaxial stresses; (3) display a clear isotope effect (hydrogen to deuterium) in the electronic spectrum when the crystal growing conditions are changed -- a clear violation of the Born-Oppenheimer approximation. They are dynamic impurities consisting of a two-atom center in a fully tetrahedral environment, in which coherent nuclear motion is coupled to the electronic degrees of freedom. Experimental data, together with group-theoretical analysis, permit a complete description of these systems.
- Publication:
-
Solid State Communications
- Pub Date:
- March 1985
- DOI:
- 10.1016/0038-1098(85)90890-7
- Bibcode:
- 1985SSCom..53.1121F
- Keywords:
-
- Conduction Bands;
- Germanium;
- Impurities;
- Particle Motion;
- Semiconductors (Materials);
- Ultrapure Metals;
- Acceptor Materials;
- Energy Spectra;
- Isotope Effect;
- Solid-State Physics