Abstract
The structural, electrostatic, and electronic properties of PbTe nanocrystals (NCs) embedded in a CdTe matrix are investigated using an ab initio pseudopotential method and a repeated supercell approximation. The calculated dot-matrix interface geometries are in excellent agreement with the plane PbTe/CdTe interfaces. The constructed rhombo-cubo-octahedron shape of the NCs corresponds to the equilibrium crystal shape and transmission-microscopy observations. We demonstrate that polar interfaces with either cation or anion termination appear predominantly in one-half space with [111] or orientation. This leads to the occurrence of a macroscopic electrostatic field, which superimposes that of the atoms. As a consequence an internal quantum-confined Stark effect is predicted. Its influence on the electronic states is discussed.
- Received 8 August 2008
DOI:https://doi.org/10.1103/PhysRevB.78.205324
©2008 American Physical Society