Consequence of layer thickness fluctuations on superlattice miniband structures

The miniband structure of a perfect superlattice depends on the thicknesses and compositions of the constituent layers. We describe simple modeling of the consequences of fluctuations in the layer thickness. Experimental results from an asymmetric superlattice tunnel diode, where the presence of negative differential conductance reflects the existence of a miniband gap, are used to show how the sensitivity of the miniband structure to such fluctuations depends on the choice of layer thicknesses.