Direct-indirect GeSn band structure formation by laser Radiation: The enhancement of Sn solubility in Ge

Onufrijevs P, Scajev P, Medvids A, Andrulevicius M, Nargelas S, Malinauskas T, Stanionyte S, Skapas M, Grase L, Pludons A, Oehme M, Lyutovich K, Kasper E, Schulze J, Cheng HH (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Optics and Laser Technology Elsevier

Book Volume: 128

Article Number: 106200

DOI: 10.1016/j.optlastec.2020.106200

Abstract

Low equilibrium solid solubility of Sn atoms in Ge (less than 1%) leads to limitations in application of this material for IR detectors and emitters. Providing of non-equilibrium conditions by powerful pulsed laser radiation can be successfully applied for enhancement of solubility of impurity atoms in the host material. Here we present laser-induced monotonous redistribution of Sn atoms in Ge, based on the thermogradient effect aiming overcoming equilibrium limitations in the solubility. We applied pulsed nanosecond laser radiation to epitaxial Ge0.96Sn0.04 layer grown on Si substrate to increase Sn atomic concentration up to 14% at the surface layer. As a result, indirect-direct graded bandgap GeSn structure was formed. The TEM/EDS cross-section analysis, X-ray photoelectron spectroscopy, Raman and UV reflection spectra confirmed the increase of Sn atomic content at the surface by order of magnitude. SEM and AFM imaging provided evident microstructure changes, while carrier lifetime changes, determined by differential transmittivity, were not observed, indicating that laser irradiation does not generate defects which reduce electronic quality of the material.

Authors with CRIS profile

Jörg Schulze

Involved external institutions

Riga Technical University LV Latvia (LV) Kaunas University of Technology (KTU) LT Lithuania (LT) Center for Physical Sciences and Technology / Fizinių ir technologijos mokslų centras (FTMC) LT Lithuania (LT) Universität Stuttgart DE Germany (DE) National Taiwan University (NTU) TW Taiwan (TW)

How to cite

APA:

Onufrijevs, P., Scajev, P., Medvids, A., Andrulevicius, M., Nargelas, S., Malinauskas, T.,... Cheng, H.H. (2020). Direct-indirect GeSn band structure formation by laser Radiation: The enhancement of Sn solubility in Ge. Optics and Laser Technology, 128. https://doi.org/10.1016/j.optlastec.2020.106200

MLA:

Onufrijevs, Pavels, et al. "Direct-indirect GeSn band structure formation by laser Radiation: The enhancement of Sn solubility in Ge." Optics and Laser Technology 128 (2020).

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