Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Direct-writing of PbS nanoparticles inside transparent porous silica monoliths using pulsed femtosecond laser irradiation | Chahadih et al. Nanoscale Research Letters 2011 6 542 http content 6 1 542 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Direct-writing of PbS nanoparticles inside transparent porous silica monoliths using pulsed femtosecond laser irradiation 1 1 1 2 3 1 1 z- . 1 Abdallah Chahadih Hicham El Hamzaoui Rémy Bernard Luc Boussekey Laurence Bois Odile Cristini Marc Le Parquier 1 Bruno Capoen1 and Mohamed Bouazaoui1 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. Introduction New directions of modern research have emerged during the last decade which has broadly been defined as nanoscale science and technology 1 2 . These new trends involve the ability to fabricate characterize and manipulate artificial structures the features of which are controlled at the nanometer scale. The semiconductor properties of lead sulfide PbS have widely been used in elements such as detectors operating in the infra-red spectral region from 850 to 3100 nm 3 solar batteries 4
