Electron Diffraction Study of the Structural Changes in a Thin GeTe Crystal Exposed to High-Power Femtosecond Laser Radiation

• Published in: Bulletin of the Lebedev Physics Institute 2023-10, Vol.50 (Suppl 5), p.S552-S559
• Main Authors: Mironov, B. N., Kochikov, I. V., Aseev, S. A., Ionin, V. V., Kiselev, A. V., Lotin, A. A., Chekalin, S. V., Ischenko, A. A., Ryabov, E. A.
• Format: Article
• Language: English
• Subjects: Ablation; Amorphization; Diffraction patterns; Electron diffraction; Femtosecond pulsed lasers; Femtosecond pulses; Germanium; Interaction of Laser Radiation with Matter. Laser Plasma; Irradiation; Photoelectrons; Physics; Physics and Astronomy; Tellurides
• ISSN: 1068-3356; 1934-838X
• DOI: 10.3103/S1068335623170086

The possibility of amorphization of a thin germanium telluride crystal irradiated by high-power 800-nm femtosecond laser pulses has been investigated. The sample was a 20-nm-thick film of crystalline semiconductor GeTe. An electron diffractometer with a source of short photoelectron pulses was used to study the structural changes. The electron diffraction patterns were analyzed, and the α- and β- phases have been identified in GeTe. It is established that sample ablation occurs in the strong field of femtosecond laser pulses, which is accompanied by a decrease in the crystalline phase thickness to 5–6 nm without any significant amorphization of the sample. A specific feature of the observed process—the absence of light-induced transition of a thin GeTe film from the crystalline to the amorphous state under femtosecond laser irradiation—is noted. Possible causes of the revealed effect are discussed.