Shape-controlled tunable homochromatic luminescence and inner photoelectric effect of hexagonal Na1.23Ca0.12Y1.28Er0.24F6 phosphors

Abstract

Novel hexagonal Na_1.23Ca_0.12Y_1.28Er_0.24F₆ nanodisks, microtubes, and nanorods were synthesized hydrothermally for the first time. Time-dependent morphology evolution showed that the resulting nanodisks, microtubes, and nanorods were synthesized by a dissolution-reconstruction formation mechanism. With the help of a 980 nm semiconductor laser, tunable homochromatic luminescence was observed by exciting single hexagonal Na_1.23Ca_0.12Y_1.28Er_0.24F₆ nanodisks, microtubes, and nanorods, respectively. Simultaneously, the inner photoelectric effect was witnessed in the hexagonal Na_1.23Ca_0.12Y_1.28Er_0.24F₆ nanodisks, microtubes, and nanorods under 980 nm excitation. We attributed anomalous inner photoelectric current to the presence of a laser stepped resonant excitation energy migration in the Na_1.23Ca_0.12Y_1.28Er_0.24F₆ matrix when a laser was applied to it. Simultaneous control of homochromatic luminescence and inner photoelectric effect were achieved by modifying morphological shapes of single Na_1.23Ca_0.12Y_1.28Er_0.24F₆ phosphors.