The morphology and composition of as-synthesized nanoparticles were characterized by SEM and EDS measurements. Their optical properties were investigated. The PL peak position of the as-synthesized Si nanoparticle ablated in air is slightly blue-shifted in comparison with those ablated in n-hexane, while it was almost no change of peak position of Si nanoparticles fabricated from p-Si in hexane and original p-Si wafer target. | Communications in Physics, Vol. 24, No. 3S1 (2014), pp. 143-148 DOI: OPTICAL PROPERTIES OF SILICON NANOPARTICLES PREPARED BY LASER ABLATION METHOD IN VARIOUS MEDIA CHU ANH TUAN Institute of Materials Science, Vietnam Academy of Science and Technology and University of Engineering and Technology, Vietnam National University, Hanoi NGUYEN THI THU TRANG, LE ANH TU, DUONG THI GIANG, PHAM HONG DUONG Institute of Materials Science, Vietnam Academy of Science and Technology PHAM THANH HUY Advanced Institute for Science and Technology, Hanoi University of Science and Technology E-mail: tuanca@ Received 04 April 2014 Accepted for publication 24 May 2014 Abstract. Bright photoluminescent silicon nanoparticles were successfully fabricated from porous silicon target in air and n-hexane using 532 nm line of YAG:Nd pulsed laser. The whole procedure was carried out at room temperature, in atmosphere . The morphology and composition of as-synthesized nanoparticles were characterized by SEM and EDS measurements. Their optical properties were investigated. The PL peak position of the as-synthesized Si nanoparticle ablated in air is slightly blue-shifted in comparison with those ablated in n-hexane, while it was almost no change of peak position of Si nanoparticles fabricated from p-Si in hexane and original p-Si wafer target. In contrast to PL intensity quenching of original p-Si sample and particles produced in air, those produced in n-hexane solvent exhibited an enhancement. The presence of dangling bonds or energy transfer from excited Si particles to oxygen molecules on the surface can be the cause of the quenching effect. Keywords: silicon nanoparticles, pulsed laser ablation, time-dependent photoluminescence spectra. I. INTRODUCTION Silicon nanoparticles have attracted much attention for their expectation of various applications such as solid state light emitting device [1], fluorescent biological labels [2, 3], and chemical sensing .
