Direct-writing of PbS nanoparticles inside transparent porous silica monoliths using pulsed femtosecond laser irradiation

Abstract

Pulsed femtosecond laser irradiation at low repetition rate, without any annealing, has been used to localize the growth of PbS nanoparticles, for the first time, inside a transparent porous silica matrix prepared by a sol-gel route. Before the irradiation, the porous silica host has been soaked within a solution containing PbS precursors. The effect of the incident laser power on the particle size was studied. X-ray diffraction was used to identify the PbS crystallites inside the irradiated areas and to estimate the average particle size. The localized laser irradiation led to PbS crystallite size ranging between 4 and 8 nm, depending on the incident femtosecond laser power. The optical properties of the obtained PbS-silica nanocomposites have been investigated using absorption and photoluminescence spectroscopies. Finally, the stability of PbS nanoparticles embedded inside the host matrices has been followed as a function of time, and it has been shown that this stability depends on the nanoparticle mean size.

Femtosecond laser induced phenomena in transparent solid materials: Fundamentals and applications

“…PbS quantum dots (QDs) are also precipited in glasses by multiple irradiation of the femtosecond laser pulses followed by heat treatment [210], whereas CdS and PbS QDs in silica xerogel are obtained using the similar radiation technique, but without conducting heat treatment [211,212]. The size and the photoluminescence can be tuned by adjusting the laser irradiation conditions.…”

Tunable growth of PbS quantum dot–ZnO heterostructure and mechanism analysis

“…The lattice spacing is measured to be 0.34 nm corresponding to the (111) plane of cubic PbS. 22,27 More information on the high resolution TEM images of the as-synthesized sample is given in the ESI † (S2).…”

Laser-induced growth of nanocrystals embedded in porous materials

“…Then, irradiation of this sample with fs pulses at 800 nm led to the rapid formation of PbS NP [40], which could be recognized not only by the brown coloration in Figure 8a but also by various characterization techniques (HRTEM, EDX analysis, electron diffraction, photoluminescence). Since the sample is initially transparent at 800 nm, the photogrowth process probably involves multiphoton absorption, but as soon as the first NP appear in the beam waist volume, one-photon absorption can occur and even becomes predominant.…”

“…(Curve a ) Just after irradiation, (curve b ) 50 days after irradiation, and (curve c ) 100 days after the initial irradiation. Adapted from [40]. …”