Near infrared photoluminescence of the univalent bismuth impurity center in leucite and pollucite crystal hosts

Abstract

The bismuth doped aluminosilicate phases leucite (KAlSi₂O₆), gallium leucite (KGaSi₂O₆) and pollucite (CsAlSi₂O₆) display broadband NIR photoluminescence. The active center, responsible for this luminescence, is the Bi⁺ monocation, which substitutes for the large alkali metal cations. The Al,Si-disorder in the aluminosilicate framework of studied crystal phases results in the heterogeneity of Bi⁺ luminescent center population, which manifests itself in the characteristic dependency of the luminescence spectrum shape on the excitation wavelength. The relation of NIR emission in Bi⁺-doped leucite and pollucite phases to the luminescent properties of bismuth-doped glasses is also discussed.