ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Novel yellow light emission from vanadyl ions-doped calcium-lithium hydroxyapatite nanopowders: structural, optical, and photoluminescence properties

Ravindranadh Koutavarapu, N. Sita Maha Lakshmi, M. Avinash, M. C. Rao, R. V. S. S. N. Ravikumar, and Jaesool Shim

School of Mechanical Engineering, Yeungnam University, Gyeongsan, Republic of Korea

E-mail: raomc72@gmail.com

Received: 20 January 2021  Accepted: 29 March 2021

Abstract:

Phosphor luminescent materials, especially those activated with transition metal ions, have been extensively investigated during the last decade because of their potential in various applications such as displays, medical imaging, lighting, and fluorescent lamps. In this study, a mechanochemical approach was used for the synthesis of novel yellow light-emitting vanadyl ion (VO²⁺)-doped calcium-lithium hydroxyapatite (CLHA) nanophosphors. The structural, morphological, optical, photoluminescence, and chromaticity properties of the as-prepared nanopowders were systematically examined. Phase structural analysis showed that the as-prepared samples were highly crystalline and corresponded to the hexagonal crystal phase of hydroxyapatite. X-ray photoelectron spectroscopy investigation indicated the existence of elements. The spectroscopic results indicate that the doped VO²⁺ ions belong to the tetragonally distorted octahedral site symmetry. The chromaticity results show that the chromaticity coordinates (x, y) for the VO²⁺-doped CLHA nanopowders were (0.448, 0.401), (0.430, 0.384), and (0.423, 0.377). The emission colors are positioned in the orange, orange-yellow, and pale-yellow regions, respectively, for VO²⁺-doped CLHA nanopowders. Thus, the light emission properties shift from orange to yellow as the dopant concentration increases from 0.01 to 0.05 mol%. These results demonstrate that phosphor materials doped with transition metal ions are suitable for display device applications.

Keywords: Hydroxyapatite; Transition metal ions; Vanadyl ions; Mechanochemical; Color correlated temperature; Yellow emission

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01632-9

Chemical Papers 75 (8) 3989–3999 (2021)