Local Conduction Band Offset of GaSb Self Assembled Quantum Dots on GaAs

GaSb self-assembled quantum dots grown by molecular beam epitaxy on GaAs exhibit a staggered (type II) band lineup with a potential barrier in the conduction band. Traditional methods cannot measure this local band offset because of the small (∼50 nm) lateral dot size. The nanometer resolution of ballistic electron emission microscopy is exploited to image individual dots and measure a local band offset of 0.08±0.02 eV.