Photothermal Effects and Heat Conduction in Nanogranular Silicon Films

Bayan Kurbanova (1) , Gauhar Mussabek (2) , Viktor Timoshenko (3, 4, 5) , Vladimir Lysenko (3, 6) , Zhandos Utegulov (1)

1 Nazarbayev University [Kazakhstan]
2 KazNU - Al-Farabi Kazakh National University [Almaty]
3 The National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) [Moscow, Russia]
4 MSU - Lomonosov Moscow State University
5 LPI RAS - P. N. Lebedev Physical Institute of the Russian Academy of Sciences [Moscow]
6 iLM - FENNEC - iLM - Formation, élaboration de nanomatériaux et cristaux

We present results on the photothermal (PT) and heat conductive properties of nanogranular silicon (Si) films synthesized by evaporation of colloidal droplets (drop-casting) of 100 ± 50 nm-sized crystalline Si nanoparticles (NP) deposited on glass substrates. Simulations of the absorbed light intensity and photo-induced temperature distribution across the Si NP films were carried out by using the Finite difference time domain (FDTD) and finite element mesh (FEM) modeling and the obtained data were compared with the local temperatures measured by micro-Raman spectroscopy and then was used for determining the heat conductivities k in the films of various thicknesses. The cubic-to-hexagonal phase transition in Si NP films caused by laser-induced heating was found to be heavily influenced by the film thickness and heat-conductive properties of glass substrate, on which the films were deposited. The k values in drop-casted Si nanogranular films were found to be in the range of lowest k of other types of nanostructurely voided Si films due to enhanced phonon scattering across inherently voided topology, weak NP-NP and NP-substrate interface bonding within nanogranular Si films.

Mots clés: silicon; nanogranular; nanoparticle; nanostructure; porous; void; drop casting; thin film; laser heating; photothermal; temperature; Raman; phonons; heat conduction; phase transition; finite element modeling; thermal conductivity; FDTD; FEM

Domaines: Sciences de l'ingénieur [physics]; Chimie; Physique [physics]; Science des matériaux [cond-mat.mtrl-sci]

Bayan Kurbanova, Gauhar Mussabek, Viktor Timoshenko, Vladimir Lysenko, Zhandos Utegulov. Photothermal Effects and Heat Conduction in Nanogranular Silicon Films. Nanomaterials, 2021, 11 (9), pp.2379. ⟨10.3390/nano11092379⟩. ⟨hal-03372646⟩