A.S. Gouralnik

The Institute of Automation and Control Processes, Russia

Title: Mg2Si film growth paradigm: How and Why. Perfect Mg2Si films for light and heat conversion into electricity

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Biography

Alexander Gouralnik studied physics in Leningrad (St. Petersburg) State University, Russia, and graduated as MS in 1976. He then joined the research Laboratory of Microstructure Control Growth at the Institute of Automation and Control Processes, Far East Branch of the Russian Academy of Sciences (IACP FEB RAS). Now he is studying optics and electro-physics of silicide films and nanostructures on the Si surface. Alexander does research in Solid State Physics, Semiconductors, Film growth, Nano-structures, Nanomagnetism, Thermoelectrics, Solar Cells Physics, and Materials ScienceHe has published more than 30 research articles in SCOPUS and WOS journals.

Abstract

Many technologies include processes dependent on temperature (T). To find the optimum, many experiments are carried out at different T. We demonstrate a more rational method of investigation of T-dependent processes on surface/interface. If the sample has a wedge-shaped temperature distribution on the surface, the processes can be studied in the whole T range simultaneously. We show how in Si samples heated to 300 – 700 °C, the T difference between the ends ~ 10 – 250 °C can be obtained. This approach allows studying the processes of film growth, surface or interface reactions, phase transformations etc more efficiently.

Mg2Si is perspective for applications in solar cells and thermoelectric elements, consists of abundant, cheap and ecologic components. Basing on the physical insight into the deposition kinetics and intermixing processes, we explain how and why Mg2Si can be grown on Si at HT [1-4]. Films grown by our ultra-fast deposition method at T ? 400 °C have the best to date quality. We demonstrate a Mg2Si film pulse-deposited onto a Si substrate having T distribution 360 – 510 °C [4]. The deposition rate was ~ 10000 nm/s. The film growth process was similar to Self-Propagating High Temperature Synthesis; it took ~0.4 c (see movie).

The cheap and ecological silicide Mg2Si looks competitive to perovskites popular now (despite often toxic). The described approaches are suitable for investigations of many other T-dependent processes and other systems.