Photonics Seminar Series: Ekaterina Zharkova, PhD student, Skoltech

On the 15th of February 2023, as part of the Photonics Seminar Series, we will have the pleasure to have PhD student from Skoltech Ekaterina Zharkova present her research on Composition-dependent photoresponse in laser-synthesized WxMo1-xS2 alloys. She will discuss the synthesis of alloyed TMDCs from precursor mixtures under laser irradiation and demonstrate how these samples may be used to build photoconductor devices.

When:  On the 15th of February 2023, Wednesday, at 17:00 MSK time
Where: New Campus room E-B2-3007 / BigBlueButton

ekaterinazharkova_avatar_1655731379-200x200About the speaker:

Ekaterina Zharkova received her B.S. in Physics from Moscow State University and her M.S. in Photonics and Quantum materials from Skolkovo institute of science and technology (Skoltech). She is currently a 2nd year PhD student at the Skoltech Center for Photonic Science and Engineering under the supervision of Prof. Sakellaris Mailis. Her project is devoted to the study of electrical and photoelectrical properties of laser-written transitional metal dichalcogenides.

Abstract:

2D transition metal dichalcogenides (2D TMDCs) are materials composed of molecular layers, within which a layer of transition metal atoms is surrounded by two layers of chalcogen atoms. TMDCs have a thickness-dependent energy band structure and, especially for MoS2, it was calculated and experimentally proven (by PL measurements) that the band gap increases and changes from indirect to direct.

The direct laser writing allows us to produce either MoS2 or WS2. If we mix precursors together it is possible to obtain the alloy. By changing the volume ratio of single-source precursors in the mixture we can change the stoichiometry. Alloy composition can be modulated. A set of 2-terminal devices with different distances between electrodes was fabricated on the base of the alloys. The photoresponse was measured by additional illumination of the device by 450nm laser. The photocurrent was linearly dependent on the applied voltage. Such a linear character illustrates that our device is a photoconductor. The dependence of photocurrent on the composition was also obtained.