The synthesis and structural characterization of boron-doped silicon-nanocrystals with enhanced electroconductivity

Boron (B)-doped silicon-nanocrystals (Si-NCs) with wavelength-tunable photoluminescence (PL) properties in the visible region are successfully prepared for the first time, leading to significant enhancement of electroconductivities. The B-doped Si-NCs are prepared on a p-type Si(100) substrate by co-deposition of p-type Si(100) chips/boron chips/silica disk targets. As the number of the B chips used as the target is increased, the amount of doped B content increases gradually. Here the amount of doped B content in the Si-NCs is controlled from 0 to 0.4, 0.7, 2.3 at.%. The B elemental states, compositional ratios, and surface condition of the obtained Si-NCs are fully characterized by high-resolution transmission electron microscopy (HRTEM) observations, micro-Raman scattering spectroscopic analysis, etc. Our B-doped Si-NCs possess both the continuous luminescence property in the visible region and enhanced electroconductivity. The red-shift of the PL peak is confirmed by the increase of the amount of doped B content. This paper should be very important from the viewpoint of application to optoelectronic devices and electroluminescent (EL) displays.