Dyrekcja Instytutu Fizyki CND zaprasza wszystkich pracowników i studentów na Otwarte Seminarium Naukowe, które odbędzie się 13-01-2021 o godz. 14:00 w formie zdalnej za pośrednictwem platformy Zoom.
Defects in semiconductors: new concepts and materials
Micro and Nanotechnology Laboratory (MiNaLab)
Department of Physics and Centre for Material Science and Nanotechnology,
University of Oslo, Pb 1048 Blindern, 0316 Oslo, Norway
This talk comprises four sections: a brief glance at the University of Oslo and the MiNaLab, a short generic introductory part explaining why defects in semiconductors are of interest in science and technology, as well as two specific examples – firstly illustrating new concepts with defects functionalization and secondly explain the interest to defect characterization in new materials.
The defect functionalization concept is illustrated with the data recently published in Nature Electronics (DOI 10.1038/s41928-020-00499-0). In this paper we showed that single photon emission, which is a fingerprint of the isolated quantum emitter – or a qubit as it often refers in literature – can be mastered in silicon (Si) by carbon (C) ion implantation; we showed that it occurs in form of the (C-Si)-defect complex or G-center as referred in literature; we concluded that silicon, among other materials, may be a suitable platform for deploying quantum technology. Thus, the functionalization of defect complexes as qubits has a great potential to revolutionize the quantum technology and fuel the projected quantum high-tech boom of the 21st century. The topic will be set in the perspective of fundamental aspects limiting the use of semiconductor qubits in quantum technologies.
The advance of defect studies in new materials is illustrated by our recent data on characterization of gallium oxide (Ga2O3). Potential technological impacts of Ga2O3 are manifold; to name just one – for power electronics – changing from the presently dominating Si (or even from more advanced SiC) to Ga2O3, will save tremendous amount of electricity otherwise lost in switching operations. As such, Ga2O3 ranks high among “energy” materials. One of the issues slowing down the use of Ga2O3 is the lack of fundamental understanding and difficulties in controlling electrically active defects. Indeed, starting from “simplest” point defects, due to the low symmetry of typically used monoclinic β-Ga2O3, there are two different configurations of Ga in the unit cell and three different environments in the O sub-lattice in β-Ga2O3. Such complexity results in equally many different vacancy configurations and sites for extrinsic impurities to reside, provoking a number of electronic states in the bandgap. Concurrently, it make the physics very interesting. To illustrate it, our recent data on defects in Ga2O3 will be reviewed (e.g. APL, 112 42104(2018); APL Mater., 112, 42104 (2019), JAP 125, 185706 (2019)).
As a general conclusion, it can be stated that the progress in physics of defects in semiconductors has resulted already in a number of paramount inventions in technology and there are promises for more breakthroughs in future.
Topic: Seminarium w dniu 13 stycznia 2021
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Meeting ID: 961 880 5240
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