Perpendicular Electronic Transport in Doping Superlattices

Electrical transport measurements are performed at liquid-nitrogen and room-temperature on doping superlattices in perpendicular direction to the quantum-well planes. The period-lengths of the doping superlattices range from 150angstroms to 600angstroms. The current-voltage characteristic in long-period doping superlattices (Type B) are strongly nonlinear and exhibit a new type of negative-differential conductivity (NDC).