Enhanced visible and near infrared emissions via Ce3+ to Ln3+ energy transfer in Ln3+-doped CeF3 nanocrystals (Ln = Nd and Sm)

Abstract

We report the enhancement of both visible and near infrared (NIR) emissions from Nd³⁺ ions via Ce³⁺ sensitization in colloidal nanocrystals for the first time. This is achieved in citrate capped Nd³⁺-doped CeF₃ nanocrystals under ultraviolet (UV) irradiation (λ_ex = 282 nm). The lasing transition (⁴F_3/2 → ⁴I_11/2) at 1064 nm from Nd³⁺-doped CeF₃ nanocrystals has much higher emission intensity via Ce³⁺ ion sensitization compared to the direct excitation of Nd³⁺ ions. The nanocrystals were prepared using a simple microwave irradiation route. Moreover, the study has been extended to Sm³⁺-doped CeF₃ nanocrystals which show strong characteristic emissions of Sm³⁺ ions via energy transfer from Ce³⁺ ions. The energy transfer mechanism from Ce³⁺ to Nd³⁺ and Sm³⁺ ions is proposed.