Dr. Aurelian Marcu, Senior Researcher II, Centre for advanced Laser Processing, National Institute for Laser Plasma and Radiation Physics, Romania

Title: Nanowires Grow using Special Laser Techniques

Abstract: Nanotechnology progress and respectively nan-devices fabrication processes are more and more relaying on the "Bottom-up" approach, and nanoparticles, nanowires and nanosheets are becoming the basic building bloks for fabricating complex nano-devices. However, physical and chemical properties control of such "bricks" is a challenging tasks and requires more and more sophisticated techniques. Laser assisted vapour-liquid-solid grow is one of the verry performant approaches, particulary for the nanowires, even if cheapper and more cost-effective chemical techniques are known to give reasonable results for regular or less demanding structural and chemical properties device applications.

In the present paper we will present some special deposition techniques based on laser techniques. Using special setups and special lasers, we will present 'eclipse', ’plasma reflection’ and respectively ‘back-side’ laser based techniques for VLS grow of oxide nanowires. Based on the obtained results comments on their performances and advantages over clasical techniques will be presented. Results interpretations will be explained in terms of plume interaction with obstacles with respect to the ablation process. We will also include some results using from a high-repetition (500 Khz) laser and a comparison between a clasic and a high-repetition laser results will be presented. For more demanding application, surface (catalyst) patterning combined with such special techniques are discussed and some examples in sensors application will also be presented.

Keywords: Nanowires, VLS-grow, Special PLD, Eclipse technique, PLR/PR, surface patterning