Sunday 09 March 2025
A team of researchers has developed a novel method for flattening nanobubbles that form in two-dimensional (2D) materials, such as transition metal dichalcogenides (TMDs), during their transfer to new substrates. These nanobubbles can significantly alter the local electric, optoelectronic, thermal, and mechanical properties of 2D materials, making them detrimental to the constructed devices.
The team’s approach, known as laser optothermal nanobombing (LOTB), uses a combination of high-intensity laser pulses and careful beam control to induce a phase transition in the material. This process creates a localized temperature increase that pulls the material into a flat shape, effectively eliminating the nanobubble.
To develop LOTB, researchers used computer simulations to model the behavior of the 2D material under different conditions. They found that by carefully controlling the intensity and duration of the laser pulses, they could create a high-temperature region at the center of the bubble, which in turn induced a phase transition and flattened the material.
The team then tested their approach using a 1L-MoS2 sample, a type of TMD commonly used in electronic devices. They found that LOTB was able to effectively eliminate nanobubbles with diameters as small as 10 nm, resulting in a significant reduction in surface roughness and improvement in the material’s optical properties.
To further improve the technique, researchers developed two variations: dual-beam cascaded LOTB and multi-shot LOTB. The former uses two laser beams of different intensities to create a high-temperature region at the center of the bubble, while the latter involves irradiating the sample with multiple pulses in quick succession. Both methods were found to be effective in expanding the flattened area and improving the elimination efficiency.
The development of LOTB has significant implications for the production of 2D material-based devices. Currently, the transfer process can result in defects and imperfections that affect device performance. By using LOTB to flatten nanobubbles, manufacturers may be able to produce higher-quality materials with fewer defects, leading to improved device reliability and performance.
In addition to its practical applications, LOTB also has theoretical implications for our understanding of 2D material behavior. The process provides insight into the dynamics of phase transitions in these materials and could potentially lead to new methods for controlling their properties.
Cite this article: “Laser-Induced Flattening of Nanobubbles in 2D Materials”, The Science Archive, 2025.
Nanobubbles, Transition Metal Dichalcogenides, Laser Optothermal Nanobombing, Phase Transitions, 2D Materials, Surface Roughness, Optical Properties, Device Performance, Defects, Imperfections
