TY - JOUR

T1 - Controlling the percolation threshold in adhesion-layer-free room-temperature nanosecond pulsed laser deposition of ultrathin gold films

AU - Kolosovsky, Danil A.

AU - Zalyalov, Timur M.

AU - Ponomarev, Sergei A.

AU - Zhivodkov, Yuri A.

AU - Shukhov, Yuri G.

AU - Morozov, Alexey A.

AU - Starinskiy, Sergey V.

N1 - AFM and SEM diagnostics of surface morphology were performed at the CKP “Nanostruktury” and funded by the Russian Science Foundation (grant No. 19-72-30023). DSMC simulations, transmission spectra measurements, and current-voltage characteristics analysis were conducted under the state contract IT SB RAS. The research is founded by the Russian Science Foundation, grant No 24-79-10070 (https://rscf.ru/project/24-79-10070/).

PY - 2026/2/28

Y1 - 2026/2/28

N2 - Ultrathin gold films deposited by pulsed laser deposition in an oxygen atmosphere at room temperature are promising for transparent and flexible electronic devices. Here, we propose a physical mechanism to control the percolation threshold of such films without cryogenic cooling or adhesion layers. We show analytically that the kinetic energy and flux of gold atoms govern island growth dynamics on the substrate. Reducing the energy-to-flux ratio decreases the critical island size for coalescence, facilitating earlier film percolation. Direct Monte Carlo simulations were used to identify the optimal ratio, and the results were validated experimentally by varying the laser spot size while keeping the fluence constant. This approach enabled the formation of conductive gold films with a percolation threshold as low as 3 nm–demonstrated for the first time. Scanning electron microscopy, atomic force microscopy, optical transmission, and current–voltage measurements confirmed the correlation between film morphology and electrical properties. Our results introduce the effective laser spot area as a tunable and scalable parameter in pulsed laser deposition, offering a new route to engineer ultrathin metal films with tailored properties. This method advances the development of next-generation optoelectronic and nanoelectronic devices based on ultrathin conductive films.

AB - Ultrathin gold films deposited by pulsed laser deposition in an oxygen atmosphere at room temperature are promising for transparent and flexible electronic devices. Here, we propose a physical mechanism to control the percolation threshold of such films without cryogenic cooling or adhesion layers. We show analytically that the kinetic energy and flux of gold atoms govern island growth dynamics on the substrate. Reducing the energy-to-flux ratio decreases the critical island size for coalescence, facilitating earlier film percolation. Direct Monte Carlo simulations were used to identify the optimal ratio, and the results were validated experimentally by varying the laser spot size while keeping the fluence constant. This approach enabled the formation of conductive gold films with a percolation threshold as low as 3 nm–demonstrated for the first time. Scanning electron microscopy, atomic force microscopy, optical transmission, and current–voltage measurements confirmed the correlation between film morphology and electrical properties. Our results introduce the effective laser spot area as a tunable and scalable parameter in pulsed laser deposition, offering a new route to engineer ultrathin metal films with tailored properties. This method advances the development of next-generation optoelectronic and nanoelectronic devices based on ultrathin conductive films.

KW - Laser spot size

KW - Percolation threshold

KW - Pulsed laser deposition

KW - Transparent conductive electrodes

KW - Ultrathin gold films

UR - https://www.scopus.com/pages/publications/105020676363

UR - https://www.mendeley.com/catalogue/4219bb04-6653-353c-8881-9f83c5aeaf2f/

U2 - 10.1016/j.apsusc.2025.165049

DO - 10.1016/j.apsusc.2025.165049

M3 - Article

VL - 719

JO - Applied Surface Science

JF - Applied Surface Science

SN - 0169-4332

M1 - 165049

ER -