Various pulsed laser deposition methods for preparation of silver-sensitised glass and paper substrates for surface-enhanced Raman spectroscopy

Silver nanoparticle films by flowing gas atmospheric pulsed laser deposition and application to surface‐enhanced Raman spectroscopy

“…These values were calculated by choosing the signal Raman peak at 1360 cm −1 and the noise value at 1335 cm −1 as described in reference. 29 The better performance here is due to the "hot spots" introduced in the film by the formation of large aggregates of particles, favorable to SERS effect. In "hot spots" the strongly confined localized electric field leads to enhancement of Raman signals, several orders of magnitude higher than a normal film.…”

“…[4][5][6][7][8][9] Different approaches for the synthesis of these NP films exist today and have been productively applied; however, APLD emerges as the most recent and striking gas-phase approach utilized for nanofabrication. [11][12][13][14][15][16][17][18][19][20][21][22][23][24] For laser ablation at atmospheric pressure, a high-density plasma (varying from n e 1.59 to 2.27× 10 18 cm −3 ) is formed for various ambient environments compared to a free expansion. 14 Thus for APLD, the density of laser-produced plasma plume is several orders of magnitude higher than encountered for a low-pressure plasma in vacuum or background gas.…”

“…14 Thus for APLD, the density of laser-produced plasma plume is several orders of magnitude higher than encountered for a low-pressure plasma in vacuum or background gas. 24,25 For the typical laser fluence value 1.4 J cm −2 , the plasma plume moves pretty slowly, typically at a velocity of 5 × 10 2 ms −1 compared to 1 to 3 × 10 4 ms −1 in a vacuum. 24 The ablation plume is thus spatially confined and leads to the formation of NPs in the vicinity close to the target surface.…”

“…24,25 For the typical laser fluence value 1.4 J cm −2 , the plasma plume moves pretty slowly, typically at a velocity of 5 × 10 2 ms −1 compared to 1 to 3 × 10 4 ms −1 in a vacuum. 24 The ablation plume is thus spatially confined and leads to the formation of NPs in the vicinity close to the target surface. This is resulting in a very low deposition yield of a nanomaterial and subsequently closely spaced deposition on the substrate.…”

“…The noble metal NP films of gold (Au) and silver (Ag) are the most commonly studied materials in scientific research due to their multitude size‐dependent physicochemical and optical properties related to surface plasmons 4‐9 . Different approaches for the synthesis of these NP films exist today and have been productively applied; however, APLD emerges as the most recent and striking gas‐phase approach utilized for nanofabrication 11‐24 . For laser ablation at atmospheric pressure, a high‐density plasma (varying from n e 1.59 to 2.27× 10 18 cm −3 ) is formed for various ambient environments compared to a free expansion 14 .…”