Luminescence Study of Water-Soluble CdS Nanoparticles Produced by Femtosecond Laser Ablation at High Laser Fluence

Abstract

Water-soluble CdS nanoparticles (NPs) with excellent colloidal stability were produced by femtosecond laser ablation at high laser fluence. The transmission electron microscope image of the obtained NPs exhibited a presence of two populations, characterized by low and high size dispersions, with different mean particle sizes. A comprehensive optical spectroscopy study of the NPs was carried out, and the results indicated a close correlation between the distribution properties and the luminescence characteristics. By analyzing the photoluminescence spectra of the CdS NPs synthesized under different focusing conditions, we revealed that the formation of the two-peak NPs distributions is related to the breakdown-induced plasma in water at such high laser fluence. However, this plasma-related ablation could manifest itself in the production of highly dispersed population, whereas the formation of the low-dispersed one is mainly attributed to the pure radiationrelated ablation. This work will help us take advantage of the ultrapulse laser to synthesize favorable watersoluble semiconductors NPs for biosensing and labeling applications.

Effects of Liquid Medium and Ablation Wavelength on the Properties of Cadmium Sulfide Nanoparticles Formed by Pulsed‐Laser Ablation

“…CdS nanoparticles with different morphologies, such as spherical and hollow spherical nanoparticles, were synthesized by using PLAL and showedablueshift to highere nergies in the optical bandgap [14] due to the size quantization effect. [11,12,13,29] The redshift (1.8 to 2.1 eV) observed in the CdS colloidss ynthesized by ablationa tl = 1064 nm may be due the formation of agglomerated CdS nanoparticles or the presence of otherp hases.C dS nanoparticles were synthesized by ablation in ag as medium at laser wavelengths of l = 266 and 355 nm, and ar edshift was observed after ablation at l = 355 nm due to the formationo fl arger nanocrystals. Also, an opticalb andgap of 2.33 eV was reported for CdS in aT iO 2 / ZnO/CdS composite synthesized by using PLAL, which represents ar edshift due to the presence of other nanomaterials.…”

“…All the emission spectra present broad peaks in the green region.I th as been reported that green emission peaks around the bulk bandgap energy is assigned as the recombination of free electrons and holes, and also that low-intensity emission peaks indicate that the CdS nanoparticles are not efficientlye xcited, and the broad emission peak implies that al arge number of particles of different sizes are excited. [13] The size variation andm orphological differences in CdS nanoparticles caused by the ablationwavelength, energy,a nd liquid medium resultedi nd ifferent opticale missions. [31] Also, CdS nanoparticles synthesized by using chemical methods displayed al ess intense broad green peak at 2.3 eV and am ore intense peak at 2.5 eV.…”

“…[10] Tunable sizes (5-12 nm) and differents hapes, such as spheres, rods, and ropes of nano CdS have been synthesized by using PLAL. [13] TiO 2 /ZnO/CdS nanocomposites with double bandgaps at 2.84 and 3.27 eV weres ynthesized by laser irradiation of am ixed solution of TiO 2 ,Z nO, and CdS (dissolvedi nd eionized water) with a l = 532 nm output from aN d:YAGl aser (350 mJ, 70 Jcm À2 ,5ns, 10 Hz). Spheroidal and nonagglomerated CdS nanoparticles in the hexagonal phase produced by femtosecond laser ablation of aC dS plate submergedi nd eionized water presented luminescent properties (emissions) at l = 420 and 540 nm.…”

“…Spheroidal and nonagglomerated CdS nanoparticles in the hexagonal phase produced by femtosecond laser ablation of aC dS plate submergedi nd eionized water presented luminescent properties (emissions) at l = 420 and 540 nm. [13] TiO 2 /ZnO/CdS nanocomposites with double bandgaps at 2.84 and 3.27 eV weres ynthesized by laser irradiation of am ixed solution of TiO 2 ,Z nO, and CdS (dissolvedi nd eionized water) with a l = 532 nm output from aN d:YAGl aser (350 mJ, 70 Jcm À2 ,5ns, 10 Hz). [14] Herein, CdS nanoparticles with different morphology,s ize, and optical properties were synthesized by using pulsed-laser ablation of aC dS target in different liquid media at two ablation wavelengths (l = 532 and 1064 nm) with different ablation energies (fluence).…”

CuInGaSe 2 nanoparticles by pulsed laser ablation in liquid medium

“…Nanocolloids synthesis was completely free of any ligands and was highly stable. Other materials having applications in solar cells and optoelectronics synthesized by PLALM include ZnS [16], PbS [16], SnS [17], CdS [18], Sb 2 S 3 [19], CdTe [20,21], CdSe [21,22] and ZnTe [21]. Here we report synthesis, morphology and properties of CIGS nanoparticles using pulsed laser ablation of a CIGS alloy target in different liquid media by varying the laser fluence and ablation wavelengths.…”