Preparation And Properties Of Ultrafine Fluorideup-conversion Luminescence Materials

Er³⁺ doped barium-natrium-yttrium-fluoride infrared-visible up-conversion luminescence phosphor sensitive to 1550 nm was synthesized by the low-temperature combustion synthesis?LCS?method.The cations batch formula,the type and dosage of fuel,the type and dosage ofdispersant,the heating temperature and the heating time were studied in system.The analysis result of the orthogonal experiments shows that the optimal batch formula of Er-Y-Ba-Na is 11:2.5:13:73.5,11:15:32:42,11:15:18:56?mol%?,respectively,when the fuel is urea,citric acid and glycine.The optimal amount of the fuel is 230%stoi.,100%stoi.and 110%stoi.,respectively,when the fuel is urea,citric acid and glycine.The dispersants Bi₂O₃,?NH₄?₂SO₄ and PEG were introduced respectively to get the uniform size nana-phosphor samples.Samples synthesized by LCS method were of a lot of surface defects because of the rapid reaction duration.In this paper,the heat treatment process was studied to repair the sample surface defects.It should be important that the grain size should grow appropriately,therefore,the optimal heating conditions determined are 600 ? for 10 min.The up-conversion emission spectrum of the samples presents the characteristic emission peaks of Er³⁺when excited at 1550 nm,in which 520 and 540 nm are corresponding to the 2H11/2 and 4S3/2 transitions to the 4I15/2 ground state,respectively,and then ⁶55nm is corresponding to the4F9/2 transitions to the 4I15/2 ground state.The I-P curve proves that the up-conversion luminescence of Ba_xNa_yY_zF_{2 x + y + 3z + 3m}: Er³⁺m results from three-photon absorption process.