title: Tunable blue-green-emitting wurtzite ZnS:Mg nanosheet-assembled hierarchical spheres for near-UV white LEDs.
abstract: Mg-doped ZnS hierarchical spheres have been synthesized via hydrothermal method using mixed solvents of ethylenediamine and DI water without any surface-active agent. The surface morphology and microstructure studies revealed that the hierarchical spheres were consisted of many well-aligned nanosheets with width 10 nm and length about 50 ~ 100 nm. X-Ray diffraction results show that the ZnS:Mg hierarchical spheres have wurtzite structure with high crystallinity. The absorption edge in the diffuse reflection spectra shifts towards lower wavelength with increasing Mg concentration, indicating an expansion in the bandgap energy that is estimated to be in the range of 3.28 to 3.47 eV. Blue-green photoluminescence with tunable intensity and peak position was observed depending on the Mg content. The Mg2+-activated ZnS phosphor can be good candidates for blue-green components in near-UV white light-emitting diodes.
authors.forename: Devulapalli Amaranatha
authors.initials: DA
authors.lastname: Reddy
authors.forename: Deok Hyeon
authors.initials: DH
authors.lastname: Kim
authors.forename: Seuk Joo
authors.initials: SJ
authors.lastname: Rhee
authors.forename: Bo Wha
authors.initials: BW
authors.lastname: Lee
authors.affiliation: Department of Physics, Hankuk University of Foreign Studies, Gyeonggi 449-791, Republic of Korea. chunliliu@hufs.ac.kr.
authors.forename: Chunli
authors.initials: C
authors.lastname: Liu