Optical properties of silver nano-cubes

• PVP capped silver nano-cubes have been prepared by chemical reduction method.
• HRTEM images show that nano-cubes has a dimension of 100 nm approximately.
• HPLC studies confirms the monodispersity of the nano-cubes.
• UV/Vis shows a peak in the visible range due to surface plasmon resonance.
• Photoluminescence study gives an emission peak in the visible range.

Here in this work we are interested in the optical properties of uniform sized cubic silver nano-crystals. These silver nano-crystals are prepared by simple chemical reduction method using PVP as a capping agent. High Resolution Transmission Electron Microscopy (HRTEM) images and X-ray diffraction (XRD) analysis reveal that the produced nano-crystals are FCC in structure with a cubic morphology having an average size of 100 nm approximately. Further High Performance Liquid Chromatography (HPLC) study reveals the monodispersity of the prepared sample. UV/Vis study shows an absorption peak due to surface plasmon resonance (SPR) in the visible range which remains steady for more than two months and after that absorption peak position gets red shifted slowly as samples becomes more aged, confirming the agglomeration after two months. Most important optical property shown by the sample is the photoluminescence (PL), which gives an emission spectra in the visible range, confirming a band gap in the silver nano-cubes. It has been observed that the different PL spectra show an emission peak at 482 nm with different intensity for different excitation wavelength.