Segregation of In to dislocations in InGaN.

Dislocations are one-dimensional topological defects that occur frequently in functional thin film materials and that are known to degrade the performance of InxGa1-xN-based optoelectronic devices. Here, we show that large local deviations in alloy composition and atomic structure are expected to occur in and around dislocation cores in InxGa(1-x)N alloy thin films. We present energy-dispersive X-ray spectroscopy data supporting this result. The methods presented here are also widely applicable for predicting composition fluctuations associated with strain fields in other inorganic functional material thin films.This work was funded in part by the Cambridge Commonwealth trust, St. John’s College and the EPSRC. SKR is funded through the Cambridge-India Partnership Fund and Indian Institute of Technology Bombay via a scholarship. MAM acknowledges support from the Royal Society through a University Research Fellowship. Additional support was provided by the EPSRC through the UK National Facility for Aberration-Corrected STEM (SuperSTEM). The Titan 80- 200kV ChemiSTEMTM was funded through HM Government (UK) and is associated with the capabilities of the University of Manchester Nuclear Manufacturing (NUMAN) capabilities. SJH acknowledges funding from the Defence Treat Reduction Agency (DTRA) USA (grant number HDTRA1-12-1-0013).This is the accepted manuscript. The final version is available at http://pubs.acs.org/doi/abs/10.1021/nl5036513