Strain contrast of dilute semiconductor GaN1-xAsx and Si1-yCy hetero-epitaxial films in annular dark field images

The lower average atomic number strained GaN
x
As
1-x
(x = 0.029 and 0.045) and Si
1-y
C
y
(y ≤ 0.015) films were found to be brighter than the higher average atomic number GaAs and Si in annular dark field (ADF) images.