SiC Natural and Artificial Superlattices for the Implementation of the Bloch Oscillation Process: A Comparative Analysis

Bloch oscillations in semiconductors have been studied for several decades. Oscillations were observed in artificial superlattices based on AlGaAs-GaAs proposed Esaki and Tsu, and the natural superlattice based on superstructures SiC. In this paper we considers some base properties of the SiC natural superlattices that are the ground for the Bloch oscillations existence in these materials and attract attention to the some main disadvantages of the artificial superlattices. The experimental detection of the Bloch oscillation-dependent physical effects in semiconductors has been an actual problem over decades.

Ultralow cross-plane lattice thermal conductivity caused by Bi–O/Bi–O interfaces in natural superlattice-like single crystals

Revealing the impact of Bi–O/Bi–O interfaces with van der Waals interactions on the formation of ultralow cross-plane lattice thermal conductivity.

THz Emission from SiC Natural Superlattice Diodes Induced by Strong Electrical Field

Recently the intense terahertz electroluminescence from monopolar n++–n– –n+ structures of 6H- and 8H-SiC of natural superlattices at helium temperatures due to Bloch oscillations was discovered. In the present work we present the THz emission spectra of bipolar n++–π–n+ structures (π is a high-resistance layer of p-type conductivity) of natural superlattices 4H-, 8H- and 15R-SiC at 7 K. The bipolar n++–π–n+ structures of 4H- and 8H-SiC were analogous to those of structures for which the negative differential conductivity effect was observed earlier for three polytypes (4H, 6H and 8H) at T=300 K. We demonstrate resemblance and differences of the spontaneous THz emission spectra for the monopolar and bipolar 4H-, 6H- 8H- and 15R-SiC natural superlattices caused by Bloch oscillations of electrons in the SiC natural superlattice.