• Venkata Reddy. G. N.

Erbium (Er³⁺) doped nanocrystalline calcium fluoride (CaF₂) has been investigated for its optical absorption and photoluminescence (PL) properties due to its relevance in photonic and up conversion applications. Nano crystalline CaF₂:Er³⁺ samples were synthesized and characterized to study the influence of Er³⁺ ion incorporation and Nano scale effects on their optical behaviour. The optical absorption spectra exhibit welldefined 4f–4f transitions of Er³⁺ ions from the ground state ⁴I₁₅/₂ to higher excited states, with slight broadening attributed to crystal field variations in the nanocrystalline matrix. Photoluminescence measurements under UV– visible excitation reveal strong green emissions corresponding to the ²H₁₁/₂ → ⁴I₁₅/₂ and ⁴S₃/₂ → ⁴I₁₅/₂ transitions, along with red emission from the ⁴F₉/₂ → ⁴I₁₅/₂ level. The prominent near-infrared emission around 1.53 μm, arising from the ⁴I₁₃/₂ → ⁴I₁₅/₂ transition, confirms the suitability of CaF₂ as a low-phonon-energy host for Er³⁺- based optical devices. The results demonstrate that nanocrystallinity enhances spectral broadening, modifies local symmetry around Er³⁺ ions, and influences emission intensity through surface-related quenching effects. These findings highlight the potential of Er³⁺-doped CaF₂ nanocrystals for applications in optical amplifiers, up conversion phosphors, and photonic materials.

calcium fluoride; phosphors; Photoluminescence; transition; photonic materials;

"Optical absorption and Photoluminescence studies of Erbium doped nanocrystalline CaF2", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.3, Issue 12, page no.876-883, December-2016, Available :http://www.jetir.org/papers/JETIR1701D75.pdf

"Optical absorption and Photoluminescence studies of Erbium doped nanocrystalline CaF2", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.3, Issue 12, page no. pp876-883, December-2016, Available at : http://www.jetir.org/papers/JETIR1701D75.pdf