Synthesis and Characterization of Nano Scale Porous Silicon Photonic Crystals for Optical Device and Sensing Applications

This paper reports the feasibility of synthesis and characterization of One Dimensional nano scale Porous Silicon Photonic Crystals (1D-PSPC) prepared using electrochemical anodization of p-type crystalline silicon wafer by adjusting the current densities. Two structures PSPC1 and PSPC2 with current density 25 and 35mA/cm with 10 minutes of etching time were prepared. Structural and optical properties of the fabricated structures are investigated using Scanning Electron Microscope (SEM), Photoluminescence (PL), reflectance and transmittance. SEM characterization confirms porous structure with average pore size 56.6 nm and 73.9 nm and the thickness 22.5 μm and 23.9 μm for PSPC1 and PSPC2, respectively. PL study shows that the electronic band gap can be tuned from 1.87 eV to 1.93 eV by adjusting the anodization current density at constant electrolyte concentration and etching time. The engineering data reported here are useful for the design and fabrication of the nano scale optical device and sensing applications.