Cluster size and Excitation wavelength dependent Photoluminescence behavior of nano colloidal Ge- Se- Sb- Ga chalcogenide glass solutions

The photoluminescence emission characteristics from Ge- Se- Sb- Ga nano colloid chalcogenide glass solutions were investigated and the results obtained are presented. The spectra show a remarkable dependence on the chalcogenide glass concentration (0.72mg to 0.12 mg in 1ml amine solvent) and the excitation wavelength (350 nm-560 nm). The energy gap of the nano colloid solutions were found to depend on cluster size which in turn depend on concentration of chalcogenide glass in solution. We have found there is a cluster size and excitation wavelength dependent shift of the luminescence peak. The excitation at the tail of the absorption band gives rise to an emission that shifts with the change of the excitation wavelength. The significant feature of this photoluminescence from these samples can be attributed to the electronic states in the bandgap of the nano colloidal solutions.