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

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 (λex = 282 nm). The lasing transition (4F3/2 → 4I11/2) 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.