Epitaxial CdTe thin films were grown on GaAs/Si(001) substrates by metal-organic chemical vapor deposition using thin GaAs as a buffer layer. The interfaces were investigated using high-resolution transmission electron microscopy and geometric phase analysis strain mapping. It was observed that dislocation cores exist at the CdTe/GaAs interface with periodic distribution. The spacing of the misfit dislocation was measured to be about 2 nm, corresponding to the calculated spacing of a misfit dislocation (2.6 nm) in CdTe/Si with Burgers vector of a/2. From these results, it is suggested that the GaAs buffer layer effectively absorbs the strain originating from the large lattice mismatch between the CdTe thin film and Si substrate with the formation of periodic structural defects.
Bibliographical noteFunding Information:
This research was supported by the Converging Research Center Program through the Ministry of Education, Science, and Technology (2011K000616).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry