Influence of implantation assisted Ni doping on structural and optical properties of WO2.72 films.

In this paper, structural and optical properties of WO 2.72 thin films implanted by 150 keV Ni ions having ion fluences in the range of 1015 to 1016 ions/cm2 have been investigated. Structural investigations (Raman and XRD) suggest the formation of the crystalline monoclinic phase of pristine films. However, after ion implantation, the crystalline quality degrades as a function of ion fluences, and complete amorphization is observed at highest fluence. Further, the bandgap decreases upon ion implantation as a result of band tailing effect. Optical investigation under UV excitation delineates the existence of NUV, band-to-band transition and blue green emission bands in WO 2.72 thin films. Implantation-assisted Ni doping blueshifted the new NUV emission peaks due to the enhancement in free electron concentration in the conduction band (CB). The overall hue of the emitted light investigated using Commission International de l'Eclairage (CIE) diagram demonstrates the transition from light to deep blue region upon Ni implantation. • Structural and optical properties of WO 2.72 thin films implanted with Ni ions were studied. • Amorphous films are obtained at high Ni fluences. • Multiple radiative transitions due to intrinsic and implantation induced defects were obtained. • Implantation-assisted doping of Ni leads to the production of oxygen vacancies. • The CIE coordinates depicts the tuning of color from light blue to deep blue. [ABSTRACT FROM AUTHOR]