Modifications in band gap and optical properties of Zn0.96−xNd0.04CuxO (x = 0, 0.05, 0.1 and 0.15) nanoparticles
- 152 Downloads
Nd-doped and Nd, Cu co-doped ZnO nanoparticles (Zn0.96−xNd0.04CuxO, x = 0, 0.05, 0.1 and 0.15) were synthesized by sol–gel method. The structural and optical properties of the samples were investigated by X-ray diffraction (XRD) and UV–visible photo-spectrometer. The synthesized nanoparticles have different microstructure without changing a hexagonal wurtzite structure. CuO phase was noticed in XRD spectra at 38.73° after Cu = 5 % which was formed from remaining un-reacted Cu2+ ions. The average crystal size was gradually increased from Cu = 0 % (17 nm) to 15 % (17.6 nm) having lowest value (16.7 nm) at Cu = 5 %. The change in lattice parameters confirmed the substitution of Cu in Zn–Nd–O lattice. The observed constant c/a ratio revealed that there was no change in hexagonal wurtzite structure by Cu-doping. The energy dispersive X-ray spectra confirmed the presence of appropriate amount of Nd and Cu in Zn–O lattice. The optical absorption was increased gradually from Cu = 0–10 % and showed maximum at Cu = 10 % due to the presence of more nucleation centres and defect states. The defects related green band between 487 and 493 nm was due to the oxygen vacancies and intrinsic defects. The higher transmittance (≈ 90 %) noticed at Cu = 15 % leads to the industrial applications. The observed blue shift in energy gap from 3.49 eV (Cu = 0 %) to 3.65 eV (Cu = 10 %) and the red shift from Cu = 10 % (3.65 eV) to Cu = 15 % (3.61 eV) can be explained by the Burstein–Moss effect. Presence of chemical bonding was confirmed by Fourier transform infrared spectra.
KeywordsNd Cu co-doped ZnO Energy gap Microstructure Optical property FTIR spectra
The authors are thankful to the University Grant Commission, Hyderabad, for financial support under the project [File No.: MRP- 4317/12 (MRP/UGC-SERO)].
- 1.Pearton SJ, Norton DP, Lp K, Heo YW, Steiner T (2004) J Vac Sci Tech B 932:1714985Google Scholar
- 19.Cullity BD (1978) Elements of X-ray diffractions. Addison-Wesley, ReadingGoogle Scholar
- 29.Palomino AP, Perez OP, Singhal R, Tomar M, Hwang J, Voyles PM (2008) J Appl Phys 103:07D121Google Scholar
- 31.Nakamoto K (1997) Infrared and Raman spectra of inorganic and coordination compounds, parts- A and B. John Wiley and Sons, New YorkGoogle Scholar
- 35.Sadtler Research Laboratories (ed.), The infrared spectra handbook of inorganic compounds (Heyden and Son Ltd., London, 1984)Google Scholar