Abstract
The dynamics of partial dislocations in CdTe have been observed at the atomic scale using aberration-corrected scanning transmission electron microscopy (STEM), allowing the mobility of different dislocations to be directly compared: Cd-core Shockley partial dislocations are more mobile than Te-core partials, and dislocation cores with unpaired columns have higher mobility than those without unpaired columns. The dynamic imaging also provides insight into the process by which the dislocations glide. Dislocations with dangling bonds on unpaired columns are found to be more mobile because the dangling bonds mediate the bond exchanges required for the dislocations to move. Furthermore, a screw dislocation has been resolved to dissociate into a Shockley partial-dislocation pair along two different directions, revealing a way for the screw dislocation to glide in the material. The results show that dynamic STEM imaging has the potential to uncover the details of dislocation motion not easily accessible by other means.
| Original language | English |
|---|---|
| Article number | 143107 |
| Journal | Applied Physics Letters |
| Volume | 109 |
| Issue number | 14 |
| DOIs | |
| State | Published - Oct 3 2016 |
Funding
This research was sponsored by the U.S. DOE, Office of Energy Efficiency and Renewable Energy, Foundational Program to Advance Cell Efficiency (F-PACE, DE-FOA-0000492), (CL, YLW, NP, YFY, SJP), the Office of DOE-BES, Materials Science and Engineering Division (ARL), DOE Grant No. DE-FG02-09ER46554 (YYZ, STP), and a user project supported by ORNL's Center for Nanophase Materials Sciences (CNMS), which is also sponsored by DOE-BES. Supercomputer time was provided by the National Center for Supercomputing Applications which is supported by the DOE Office of Science under Contract No. DE-AC02-05CH11231, and the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant No. ACI-1053575. Chen Li [No. 656378] and Timothy Pennycook [No.655760] are currently funded by the European Union's Marie Skłodowska-Curie Grants.