Two-step synthesis of a novel red-emitting Ba2ZrF8:Mn4+ phosphor for warm white light-emitting diodes. (November 2018)

• Record Type: Journal Article
• Authors: Gu, Ming; Tian, Yue; Cui, Cai'e; Huang, Ping; Wang, Lei; Shi, Qiufeng
• Is Part Of: Materials research bulletin. Volume 107(2018)
• Page Start: 242
• Page End: 247
• Publication Date: 2018-11
• Subjects: Red phosphor -- Ba2ZrF8Mn4+ -- Energy transfer -- White light-emitting diodes; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2018.07.031
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: The novel red-emitting Ba2 ZrF8 :Mn 4+ phosphor was prepared by two-step method at low temperature, which exhibits intense excitation broadband centered at ∼ 460 nm and sharp emission lines at ∼630 nm. Highlights: A novel red-emitting Ba2 ZrF8 :Mn 4+ was prepared by two-step method at low temperature. The phosphor shows an intense red emission under 460 nm excitation matching well with blue LED chip. The energy transfer between Mn 4+ was confirmed to be electric dipole-quadrupole interaction. Abstract: A novel red-emitting Ba2 ZrF8 : Mn 4+ phosphor was prepared by two-step method at low temperature, where critical precursor K2 MnF6 was prepared first by the reduction of KMnO4 using H2 O2 as reducer. The crystal structure and morphology of the phosphor was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS), showing single phase product. Luminescent properties of the phosphor were investigated by photoluminescence spectroscopy (PL) and decay curves. The molar ratio of KMnO4 : KHF2 was confirmed to play the key role in improving the luminous efficiency. More importantly, the phosphor exhibits a broadband excitation from 300 to 520 nm due to 4 A2g → 4 T1g and 4 A2g → 4 T2g transition of Mn 4+, matching well with blue LED chips. Under 465 nm excitation, intense red emission at around 630 nm with high color purity is achieved, suggesting the red-emitting phosphor has great potential for white light-emitting diodes (wLEDs).