Synthesis of nanocrystalline α - Zn2SiO4 at ZnO–porous silicon interface: Phase transition study

Thermal annealing induced formation of nanocrystalline Zinc silicate (α-Zn2SiO4) at the interface of ZnO–porous silicon (PSi) nanocomposites is reported. The PSi templates were formed by electrochemical anodization of p-type (100) Si and ZnO crystallites were deposited on the PSi surface by a Sol–gel spin coating process. The formation of α-Zn2SiO4 is confirmed by glancing angle X-ray diffraction and Fourier transform infrared spectroscopy studies. The presence of intense yellow-green emission also confirms the formation of α-Zn2SiO4. The mechanism of silicate phase formation at the ZnO–PSi interface and the origin of various photoluminescence (PL) bands are discussed in view of its potential applications in advanced optoelectronic devices.