TY - JOUR

T1 - Interaction of low-fluence femtosecond laser pulses with a composite layer containing Ge nanoclusters: A novel type of nanofoam formation

AU - Astankova, K. N.

AU - Kozhukhov, A. S.

AU - Krivyakin, G. K.

AU - Zhivodkov, Y. A.

AU - Sheglov, D. V.

AU - Volodin, V. A.

N1 - Funding Information: The authors are grateful to the colleagues from Laser Zentrum Hannover for laser treatments of the composite GeO2 layers. The authors would like to express their gratitude to the Collective Use Center “VTAN” of Novosibirsk State University and to the Collective Use Center “Nanostructures” of the Institute of Semiconductor Physics for providing all necessary equipment. The work was supported by the Russian Science Foundation (Grant No. 19-72-30023). Publisher Copyright: © 2022 Author(s).

PY - 2022/5/1

Y1 - 2022/5/1

N2 - In the present work, the low-fluence nonablating femtosecond laser irradiation (λ = 800 nm) of the GeO2 layer with Ge nanoclusters protected by SiO2 layers is studied by different types of microscopy (optical microscopy, atomic force microscopy, and scanning and transmittance electron microscopy) and Raman spectroscopy. After the laser modification, the multilayer thickness increased by 6%-29% depending on the laser fluence. It was found that the laser fluence of ∼40 mJ/cm2 was the optimal value for observing the swelling effect and was below the ablation threshold. Irradiation at this fluence led the Ge nanoclusters to decrease in size from 5-8 to ∼2 nm and crystallize, while the GeO2 matrix expanded due to the formation of GeO bubbles. The fabrication mechanism of the novel type of nanofoam consisting of a glassy matrix, cavities filled with gas, and semiconductor nanocrystals with reduced size dispersion is discussed. Presumably, this effect is associated with the selective absorption of IR (800 nm) laser radiation by Ge nanoclusters.

AB - In the present work, the low-fluence nonablating femtosecond laser irradiation (λ = 800 nm) of the GeO2 layer with Ge nanoclusters protected by SiO2 layers is studied by different types of microscopy (optical microscopy, atomic force microscopy, and scanning and transmittance electron microscopy) and Raman spectroscopy. After the laser modification, the multilayer thickness increased by 6%-29% depending on the laser fluence. It was found that the laser fluence of ∼40 mJ/cm2 was the optimal value for observing the swelling effect and was below the ablation threshold. Irradiation at this fluence led the Ge nanoclusters to decrease in size from 5-8 to ∼2 nm and crystallize, while the GeO2 matrix expanded due to the formation of GeO bubbles. The fabrication mechanism of the novel type of nanofoam consisting of a glassy matrix, cavities filled with gas, and semiconductor nanocrystals with reduced size dispersion is discussed. Presumably, this effect is associated with the selective absorption of IR (800 nm) laser radiation by Ge nanoclusters.

UR - http://www.scopus.com/inward/record.url?scp=85126627904&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/3a7df7f1-baae-332b-979c-39256f4c6914/

U2 - 10.2351/7.0000620

DO - 10.2351/7.0000620

M3 - Article

AN - SCOPUS:85126627904

VL - 34

JO - Journal of Laser Applications

JF - Journal of Laser Applications

SN - 1042-346X

IS - 2

M1 - 022002

ER -