Size-Dependent Structures and Optical Absorption of Boron-Hyperdoped Silicon Nanocrystals

Hyperdoping silicon nanocrystals (Si NCs) is emerging as an effective means to obtain novel properties such as localized surface plasmon resonance (LSPR) from Si. Here it is shown that the physical properties and in particular the LSPR of boron (B)-hyperdoped Si NCs significantly change as the NC size decreases from 6.8 to 2.4 nm. While the largest Si NCs undergo a stronger reduction of the average lattice spacing upon doping with respect to the smallest ones, they suffer much less from disorder and show LSPR over a wider range of B concentration. As a result, by taking advantage of the tunability of the NC size and doping level, the LSPR energy can be changed, making attractive the development of novel Si structures and devices based on B-hyperdoped Si NCs.