Fig. 1: Structure and morphology characterizations of MLnS2:Er3+.
From: Towards highly efficient NIR II response up-conversion phosphor enabled by long lifetimes of Er3+
a, b XRD patterns of MYS2:Er3+ (M = Li, Na, K) and NaLnS2:Er3+ (Ln = La, Y, Lu, Gd) prepared at 1173 K. c Radius ratios between the trivalent lanthanide ion and the monovalent alkali metal ion (RLn3+/RM+) of MLnS2 (M = Li, Na, K; Ln = La, Y, Lu, Gd), the cubic and trigonal phases are divided by the green dotted line. d, e Crystal structure models of cubic NaLaS2 (α-NaLaS2) and trigonal NaYS2 (β-NaYS2). f XRD patterns of β-NaYS2 doped with 2, 5, 10, 15 mol% Er3+. TEM, HRTEM images, and corresponding SAED of g–i α-NaLaS2 and j–l β-NaYS2. Source data is provided in this paper.
