Enhanced red emission in Ca0.5La(MoO4)2:Eu3+ phosphors for UV LEDs. Issue 116 (9th November 2015)

• Record Type: Journal Article
• Authors: Shi, Yurong; Liu, Bitao; Liu, Bo; Li, Chunyang; Wang, Zhenling
• Is Part Of: RSC advances. Volume 5:Issue 116(2015)
• Page Start: 95953
• Page End: 95959
• Publication Date: 2015-11-09
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra21208a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : La 3+ was introduced into CaMoO4 to form a novel compound with the chemical formula Ca0.5 La(MoO4 )2 and was synthesized by a solid-state reaction method. Abstract : La 3+ was introduced into CaMoO4 to form a novel compound with the chemical formula Ca0.5 La(MoO4 )2 and Eu 3+ activated the new compound was synthesized by a solid-state reaction method. An enhanced red emission at 615 nm originating from the 5 D0 – 7 F2 transition of Eu 3+ was reported in the Ca0.5 La(MoO4 )2 :Eu 3+ phosphor. XRD patterns indicate a structural similarity to CaMoO4 . The red emission intensity of the Ca0.5 La(MoO4 )2 :Eu 3+ phosphor is 5.92 times higher than that of CaMoO4 :Eu 3+ . Photoluminescent spectra, diffuse reflection spectra and lifetime measurements indicate that the red emission enhancement is due to the increase of the 7 F0 – 5 L6 absorption intensity of Eu 3+ in the distorted crystal field of the Ca0.5 La(MoO4 )2 :Eu 3+ phosphor. Enhanced red emission, stronger 7 F0 – 5 L6 absorption intensity, and high color purity indicate that the Ca0.5 La(MoO4 )2 :Eu 3+ phosphor is a promising red phosphor for UV LEDs. The luminescence properties of the Bi 3+ co-doped Ca0.5 La(MoO4 )2 :Eu 3+ phosphor was also investigated. Although Bi 3+ co-doped into the Ca0.5 La(MoO4 )2 :Eu 3+ phosphor broadens PLE spectra in the UV range and makes it more suitable for UV pumped LEDs, it decreases the distortion and induces a new quenching path, and thus makes the emission intensity decrease.