Investigation of metal-insulator-metal-insulator-metal structures

Results are reported for a theoretical and experimental study of negative differential resistance in double-insulating-layer metal-insulator-metal structures (MIMIM structures). A planar structure in which the insulating layers are separated by a thin layer of metal is examined theoretically. Experimental results are presented for MIMIM structures consisting of quartz substrates on which either layers of Au, MgO, Al, Al2O3, and Al or alternate layers of Al and Al2O3 were deposited. The latter structure was successfully used to generate electromagnetic radiation at a frequency of 180 kHz with a tuning range of 30 kHz (the former structure apparently melted when put to the test of experiment). The parameters of a frequency-tunable laser based on a MIMIM structure are calculated theoretically.