Enhanced photoluminescence and energy transfer behavior in Ba3Lu4O9:Bi3+,Eu3+ for flexible lighting applications

Abstract In this work, we report a color-tunable green-orange-emitting phosphor by introducing Bi3+ and Eu3+ into Ba3Lu4O9 host lattice. The emission spectra of Ba3Lu4O9:Bi3+,Eu3+ cover the whole visible spectral region, and present both the typical emissions from 3P1 – 1S0 transitions of Bi3+ and 5D0,1 – 7FJ transitions of Eu3+. The energy transfer behavior in the phosphor has been verified, based on which the emitting color of Ba3Lu4(0.98-y)O9:0.08Bi3+,4yEu3+ (y = 0–0.08) can be tuned from yellowish green (0.3188, 0.4491) to orange (0.5304, 0.3871). The phosphor Ba3Lu3.6O9:0.08Bi3+,0.32Eu3+ shows 33.3% improvement in emission intensity of Eu3+ compared with that of Ba3Lu3.92O9:0.32Eu3+. Moreover, soft polydimethylsiloxane/phosphor composite films were prepared utilizing the Ba3Lu4O9:Bi3+,Eu3+. Intense green-orange emissions suggest that the phosphors and corresponding s-PDMS-based films can be considered as promising candidates for near-UV pumped lighting and flexible devices.