A novel red phosphor Ca2YNbO6:Eu3+ for WLEDs. (27th June 2022)

• Record Type: Journal Article
• Authors: Shi, Youzhen; Cui, Ruirui; Gong, Xinyong; Deng, Chaoyong
• Is Part Of: Luminescence. Volume 37:Number 8(2022)
• Page Start: 1343
• Page End: 1351
• Publication Date: 2022-06-27
• Subjects: Ca2YNbO6:Eu3+ -- double perovskite -- phosphors -- thermal stability; Luminescence -- Periodicals; Bioluminescence -- Periodicals; Chemiluminescence -- Periodicals; Luminescence -- Periodicals; 535.35
• DOI: 10.1002/bio.4304
• Languages: English
• ISSNs: 1522-7235

Abstract

Abstract: Due to the advantages of good physicochemical properties, thermal stability, and optical properties, double perovskite compounds have received extensive attention. On this basis, a new type of red phosphor, Ca2 YNbO6 : x Eu 3+, was synthesized using a high‐temperature solid‐phase method. Its phase purity, morphology, elemental composition, absorption spectrum, photoluminescence, thermal stability, and Commission Internationale de l'éclairage (CIE) chromaticity coordinates were thoroughly investigated. The results display that there is no impurity phase in the samples and the convergence factor Rwp = 14.2%; the microscopic particles are uniform and full, and the distribution of each element is uniform. The energy band gap ΔE is between 3.71 eV and 3.65 eV. The luminescence intensity is the best when the doped Eu 3+ concentration x reaches 0.4, and emits 612 nm red light ( 5 D0 → 7 F2 ) under 465 nm excitation, and the concentration quenching is attributed to a d–d interaction. The luminescence intensity at 425 K was still 75% of the room temperature luminescence intensity, which indicates that the thermal stability is extremely superior. The CIE chromaticity coordinates (0.6534, 0.3455) of the Ca2YNbO6:0.4Eu 3+ phosphors are very close to National Television Standards Committee (0.670, 0.330), and the samples have low correlated colour temperature (2656 K) and high colour purity (99.90%). All findings suggest that Ca2 YNbO6 :Eu 3+ can serve as a substitute for red phosphor in WLEDs. Abstract : They exhibited bright red emissions at ~612 nm upon 465 nm blue light excitation. At 425 K, the luminous intensity is still 75.2% of that at room temperature. The Ca2 YNbO6 :0.4Eu 3+ sample had excellent colour purity up to 99.90%.