Quantitative strain mapping of InAs/InP quantum dots with 1 nm spatial resolution using dark field electron holography

The optical properties of semiconductor quantum dots are greatly influenced by their strain state. Dark field electron holography has been used to measure the strain in InAs quantum dots grown in InP with a spatial resolution of 1 nm. A strain value of 5.4% +/- 0.1% has been determined which is consistent with both measurements made by geometrical phase analysis of high angle annular dark field scanning transmission electron microscopy images and with simulations. (C) 2011 American Institute of Physics. [doi:10.1063/1.3672194]