Interface roughness scattering in normal and inverted In0.53Ga0.47As—In0.52Al0.48As modulation-doped heterostructures

A new model for interface roughness scattering in modulation-doped (MD) heterostructures, based on the physical structure of a molecular beam epitaxy- (MBE) grown heterointerface, is formulated. The parameters describing interface roughness have been derived from growth studies and analysis of photoluminescence linewidths of quantum wells. The model has been applied to analyze low-temperature electron mobilities in normal and inverted In0.53Ga0.47As-In0.52Al0.48As MD heterostructures. It is found that the mobility in the normal heterostructure is limited by alloy scattering, whereas both alloy and interface roughness scattering play equally dominant roles in the inverted structure.