Femtosecond laser nanoablation of glass in the near-field of single wall carbon nanotube bundles

Abstract

This paper presents an experimental study on the femtosecond (fs) laser ablation of bundles of single wall carbon nanotubes (SWCNTs) deposited on glass and the resulting nanoablation of glass beneath the bundles. The peak ablation threshold of SWCNT bundles is 50 ± 12 mJ cm −2 , which is about ten times lower than the theoretical ablation threshold of individual SWCNTs. Nanoscale ablation of the glass surface (30-50 nm wide, 20-50 nm deep and micrometres long) directly beneath the bundles is possible at a laser fluence of 920 ± 76 mJ cm −2 , which is 4-5 times lower than the fs laser ablation threshold of glass. We attribute these reduced ablation thresholds to the enhancement of fs laser pulses in the near-field of nanotube bundles. This nanoablation approach can be used for lithographical and surgical applications requiring nanoscale precision.

Femtosecond laser modification of an array of vertically aligned carbon nanotubes intercalated with Fe phase nanoparticles

“…Once the ablation threshold is reached, the topmost layer starts to ablate away, i.e., both CNTs and the Fe phase nanoparticles. The ablation of the two materials (C and Fe) occurs since the energy density even of a single pulse (0.48 J/cm 2 ) exceeded both of the reported ablation thresholds of various carbonaceous materials (multiwall CNTs, 0.046 J/cm 2 [39]; single wall CNTs, 0.05 J/cm 2 [40,41]; graphite, 0.13 J/cm 2 [42]; graphene, 0.20 J/cm 2 [43]); and the ablation threshold of iron, 0.18 to 0.19 J/cm 2 [44,45]. The gradual ablation of the CNT array leads to the formation of the cavity of approximately 10 μm depth.…”

IR femtochemistry on the surface of wide-gap ionic crystals

“…The enhancement of the electric field on carbon nanotubes is well known, which is related to their high aspect ratio l/d (up to ~10 3 ), where l is the length of the nanotube, and d is its diameter [22]. For example, the authors of [23] studied the femtosecond (λ = 780 nm) laser ablation of bundles of single wall carbon nanotubes (SWCNTs) deposited on glass and the resulting nanoablation of glass directly beneath the bundles. The peak ablation thresholds of SWCNT bundles and nanoscale ablation of the glass are up to ten times lower than the ablation threshold of individual nanotubes or glass.…”

Femtosecond laser ablation of single-wall carbon nanotube-based material

“…Meanwhile, ablation mechanisms for semiconducting and metallic SWCNTs with variable diameter-and chiralitydependent optical absorption spectra [17] by short (nanosecond) and ultrashort (femtosecond, fs) laser pulses are still far from well understood. Drastically different ablation thresholds, either exceeding 0.5 J cm −2 [4,6] or tending toward ten-times-lower magnitudes ≈ 50 mJ cm −2 [11,14,15] were reported. Apparently, because of the hierarchical organization of bulk CNT materials with individual nanotubes as elementary structural units, microscopic (intrinsic) laser ablation of individual CNT species, requiring high laser fluences owing to high optical and thermal SWCNT strength, and low-fluence mesoscopic (extrinsic) laser ablation of their arrays, bundles or bundle complexes in pressed pellets or dried residues with Laser Physics Letters Femtosecond laser ablation of single-wall carbon nanotube-based material significant contamination by soot and metal particles are possible, but were not distinguished so far.…”

“…SWCNT thin films are also key elements of passive light modulators for femtosecond lasers [7,8], electro-optical switches [9] and IR-laser protective coatings [10]. Moreover, SWCNTs may serve as seeding 'ablation centers', which initiate the supporting substrate etching due to the local field enhancement, in laser lithography schemes with improved spatial resolution [11]. CNTs were proposed as specifically adhesive, highly optically absorbing species for nano-surgery, capable of triggering ablation in nanoscale intracellular regions [12].…”