Delineating the role of defect and compositions in luminescent ZnO-ZnGa2-xAlxO4:Cr3+ micro composites towards efficient photon utilization

• Published in: Journal of luminescence 2023-05, Vol.257, p.119730, Article 119730
• Main Authors: Gupta, Santosh K., Sudarshan, Kathi, Rawat, N.S., Tyagi, Mohit, Mohapatra, M.
• Format: Article
• Language: English
• Subjects: Chromium; Composite; Defect; Persistent; Radioluminescence; Spinel
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2023.119730

In an era when materials are a boon to sustainable development and several economic reforms; the one which displays multifunctionality would attract both industry as well as academia. Moreover to reduce the global energy crunch towards electrification there is an urgent need to devise multifunction luminescent materials. Here in this work we worked on Cr3+ activated ZnO-ZnGa2-xAlxO4 spinel. These materials were found to be very effective in energy conversion of UV and X-ray photons into deep red light, displaying efficient photo and radioluminescence (PL and RL). PL intensity was triggered by lowering down of symmetry around Cr3+ ions whereas persistent and radioluminescence seems to be governed by antisite defects. Maximum PL emission intensity was observed for the composite ZnO-ZnGa1.9Al0·1O4 whereas persistent luminescence (PerL) intensity as well as lifetime emerges victorious for ZnO-ZnGa1.85Al0·15O4· Al substitution in the Ga lattice reduced the PerL while in the case of composites, there seems to be optimal value of Al that can enhance PL. It is to be noted that though PL intensity could be improved upon initial doping of Al in the composite, no such increase in RL intensity is observed and the entire Al substituted composites showed lower RL with maximum intensity was observed in ZnO-ZnGa2O4 composite. This work will pave a unique pathway to improvise the need based improved light emission in ZnO-ZnGa2O4 composite by aluminium doping and defect engineering. [Display omitted] •Energy conversion of UV and X-ray photon into deep red light.•PL and RL intensity was triggered by Cr–Cr ion pair and antisite defects respectively.•Maximum PL emission intensity was observed for the composite ZnO-ZnGa1.9Al0·1O4.•Al substitution in the Ga lattice reduced the Persistent luminescence.•Al substituted composites showed lower RL.