Capacitance-voltage spectroscopy of self assembled ordered arrays of quantum dots

Compound semiconductor quantum dots, self-assembled into a two-dimensional regimented hexagonal close-packed array, have been studied by capacitance-voltage spectroscopy. The dots were synthesized by electrodepositing a semiconductor in a nanoporous alumite template formed by the anodization of aluminum. The capacitance-voltage characteristic indicates that the dots have n-type carriers and the Fermi level is unpinned. The capacitance traces out the regions of accumulation, depletion and inversion showing that carrier modulation is possible with a gate potential. Thus, these structures are ideally suited for quantum-dot flash memories.