Anurag Pandey
Department of Physics, University of the Free State, P. O. Box 339, Bloemfontein 9300, South Africa. & Ballipur, Banewara, Mariyahu, Jaunpur, Uttar Pradesh, 222128, India.

Sumit Kumar
Department of Chemistry, Bharat Sevak Samaj College, Supaul, B. N. Mandal University, Madhepura, Bihar, India.

Promod Kumar
Laboratoire Hubert Curien, UMR 5516, Universit´e Jean Monnet Saint-Étienne, CNRS, 42023, Saint-Etienne, France

R. E. Kroon
Department of Physics, University of the Free State, P. O. Box 339, Bloemfontein 9300, South Africa.

Vinod Kumar
Department of Physics, The University of the West Indies, St. Augustine, Trinidad and Tobago.

H. C. Swart
Department of Physics, University of the Free State, P. O. Box 339, Bloemfontein 9300, South Africa.

DOI https://doi.org/10.33889/PMSL.2026.5.2.022

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Abstract

The upconversion (UC) emission behavior of Er3+-activated Zn2GeO4 phosphors synthesized using a solid-state reaction technique was reported. A series of phosphors was prepared by varying the dopant concentration to optimize the emission for optical purposes. The phase formation of the Zn2GeO4 was confirmed through X-ray powder diffraction analysis, and a negligible effect of the dopant on the structure was found. Scanning electron microscopy analysis was performed to examine the grain size and its formation. It was found that micro-sized, well-arranged grains were present throughout the phosphor. The influence of doping concentration on the UC emission spectra has been recorded by using 980 nm excitation. The comparison of UC emissions shows 2 mol% of Er3+ is the optimum doping concentration in the present host to achieve maximum upconversion emission. A schematic energy level structure is proposed to display the observed upconversion emission of the Zn2GeO4:Er3+ phosphor.

Keywords- Upconversion, Zn2GeO4, Erbium ions, Concentration dependence, Two photon processes.

Citation

Pandey, A., Kumar, S., Kumar, P., Kroon, R. E., Kumar, V., & Swart, H. C. (2026). Optimization of Doping Concentration for Upconversion Emission from Zn2GeO4:Er3+ Phosphor. Prabha Materials Science Letters, (2), 403-411. https://doi.org/10.33889/PMSL.2026.5.2.022.