Laser synthesis of uniform silicon single nanodots

Uniform silicon single nanodots were synthesized by laser ablation with a differential mobility analyzer (DMA) technique. The Si nanoparticles generated by laser irradiation of a silicon target were actively classified by a DMA and were impacted on the solid surface by a nanoparticle beam. By measuring the current of the beam, we determined the size distribution of generated particles in situ. From transmission electron microscope (TEM) observation of deposited dots, it was found that they were well-isolated and uniform in size. High-resolution TEM images indicated that they were single crystals with a diameter of 10, 7, and 5 nm. However, the particles less than 4 nm seemed to have no crystallinity (amorphous).