Effect of CuO addition on the optical and electrical properties of sodium zinc borophosphate glasses

Sodium borophosphate glasses doped with copper ions having general composition 20Na2O–20ZnO–25B2O3–(35-x) P2O5–x CuO (x=1–8 mol %) were prepared using conventional melt-quench method and characterized by density, UV–visible optical absorption, photoluminescence and conductivity measurements. Eoptical values for different glass samples are found to decrease systematically from 3.5 to 2.5 eV with increase in CuO content in the glass. Network modifying action of CuO with the glass network has been confirmed from the UV–visible optical absorption studies. Presence of Copper in the form of Cu+ species has been confirmed from photoluminescence measurements. The electrical conductivity (σ) increases with increase in copper oxide content in the glass and temperature dependence of electrical conductivity confirmed the semiconducting nature of the samples.