AbstractHigh quality thin films of HTS have been grown by MOCVD on substrates with artificial steps of predefined height and width. The surface of the films grown on the steps having width equal to the ‘double of the migration length' of the atomic species depositing on the substrate is totally free of precipitates: precipitates are gathered at the step edges where the free energy is lowest. The method has several advantages: it is simple, universal (it is independent of the materials, substrates, deposition technique or application) and allows control of precipitates segregates so that the quality and growth conditions of the films are the same as for the films grown on conventional substrates. The method is expected to result in new opportunities for the device fabrication, design and performance. As an example we present successful fabrication of a mesa structure showing intrinsic Josephson effect. We have used thin films of Bi-2212/Bi-2223 superstructure grown on (001) SrTiO3 single crystal substrates with artificial steps of 20 μm.
Aggregation of atomically precise graphene nanoribbons
