Room-temperature photoluminescence in structurally disordered SrWO4

Abstract

Intense and broad visible photoluminescent (PL) band in structurally disordered SrWO4 compounds was observed at room temperature. The polycrystalline scheelite strontium tungstate (SrWO4) samples prepared by the polymeric precursor method at different temperatures of annealing were structurally characterized by x-ray diffraction and Fourier transform Raman spectroscopy measurements. Quantum-mechanical calculations showed that the local disorder in the cluster of the network modifiers Sr has a very important role in the charge transfer. The experimental and theoretical results are in good agreement, indicating that the generation of the intense visible PL band can be related to short-range order-disorder degree in the scheelite structure.

Different Origins of Green-Light Photoluminescence Emission in Structurally Ordered and Disordered Powders of Calcium Molybdate

“…Ongoing intensive research interest with these materials can be attributed to their wide usage as phosphors, laser materials, and scintillation detectors. [1][2][3][4] Calcium molybdate, CaMoO 4 (powellite, CM), is an important material within the scheelite family AXO 4 , occurring with relatively large cations (A ) Ca, Ba, Sr, Pb) and tetrahedral anions XO 4 2-(X ) Mo, W). 5 A variety of new fields for the application of these materials have emerged recently such as new generation of cryogenic detectors.…”

Contribution of structural order-disorder to the green photoluminescence ofPbWO4

“…We are focusing on the effect of periodic local structural deformation among the numerous possible irregularities. This strategy of models with the coexistence of different types of environments around the network former has already been successfully employed in studying the PL emission in orderdisordered structures of scheelite tungstates [51][52][53] and of perovskite titanates. [54][55][56][57][58][59] In the case of the perovskite titanates, the cationic environments had fivefold MO 5 ͑M =Ti,Zr͒ and sixfold MO 6 coordinations.…”

Evolution of photoluminescence as a function of the structural order or disorder in CaMoO4 nanopowders

“…[15][16][17][18] Our group recently demonstrated that the green PL component increases along with the structural order, and that when the structure is not completely ordered it displays intense visible PL at room temperature. [19][20][21] Considering that the CPM is an efficient soft chemical method to prepare complex oxide materials and that there are controversial interpretations of the PL spectra of molybdate, this work reports on the preparation of ordered and disordered CaMoO 4 nanopowders by CPM and on their characterization. Various complementary characterization techniques were used, including x-ray diffraction ͑XRD͒, optical reflectance spectroscopy, Fourier transform infrared ͑FTIR͒ spectroscopy, and PL spectroscopy to obtain a clearer picture of the physics underlying the luminescence behavior of ordered and disordered CaMoO 4 scheelite structures.…”