Eu(3+) and Cr(3+) doping for red cathodoluminescence in ZnGa2O4

• Published in: Journal of materials research 2001-05, Vol.16 (5), p.1429-1433
• Main Authors: Rack, Philip D, Peterson, Jeffrey J, Potter, Michael D, Park, Wounjhang
• Format: Article
• Language: English
• ISSN: 0884-2914
• DOI: 10.1557/JMR.2001.0199

Cathodoluminescence emission spectra and photoluminescence (PL) excitation spectra were used to evaluate Eu(3+) and Cr(3+) as activators for red luminescence in ZnGa2O4. In the ZnGa2O4:Eu materials red emission from Eu3+ and blue intrinsic emission were observed. The blue intrinsic emission increased relative the Eu(3+) emission with increasing current density and is attributed to preferential current saturation of the Eu(3+) activators. In addition, PL excitation measurements revealed that the inefficient energy transfer from the ZnGa2O4 host to the Eu(3+) is due to poor spectral overlap between the ZnGa2O4 emission and the Eu(3+) absorption. Cr-doping resulted in a saturated red-color, and no host emission was observed over the entire current density regime investigated. The PL excitation of the ZnGa2O4:Cr revealed good overlap between the ZnGa2O4 host and the Cr(3+) absorption. Efficient energy transfer to the Cr(3+) activators occurs via multipolar interactions. (Author)