Three-dimensional Si (Ge) nanocrysials (NCs) were dispersed within the nanopores of mesoporous silica films by high-density plasma (HDP). low-density plasma, or implantation. Surface states of the resulting Si (Ge) NCs/silica arrays initiate blue-white photoluminescence (PL). HDP makes reactive species highly mobile and enables deposited NCs bonded with pore-wall well, therefore, efficiently constructing photoemission arrays. The mean density of HDP-synthesized semiconducting NCs is as high as 1 × 10 18/cm3. Accordingly, blue PL of arrays obtained with HDP, which is 4-7 times stronger than those obtained with other methods, exhibits quantum-efficiency of 1%, near the reported value for green-to-red light emission from quantum-confined Si NCs.