Novel high-efficiency violet-red dual-emitting Lu2GeO5: Bi3+, Eu3+ phosphors for indoor plant growth lighting

A batch of Bi3+/Eu3+ co-doped Lu2GeO5 phosphors were synthesized by high-temperature solid-state reaction, and the corresponding X-ray diffraction, excitation and emission spectra, energy transfer (ET) mechanism, and temperature-dependent spectra of the Lu2GeO5: xBi3+, yEu3+ (abbreviated as LGO: xBi3+, yEu3+) phosphors were systematically studied. In LGO:xBi3+, yEu3+ phosphors, the Bi3+ and Eu3+ ions occupied the Lu3+ sites and they resulted in violet-red dual-emission bands in the 300–750 nm wavelength range under 313 nm excitation. The ET from Bi3+ to Eu3+ could be found in the as-prepared LGO: 3%Bi3+, yEu3+ samples, and the ET efficiency reach as high as 91% when y = 16%. The LGO: 3%Bi3+, 5%Eu3+ phosphors showed high quantum efficiency of 43% and good thermal stability (I423K/I303K = 51%). Importantly, the emission curve of the LGO: 3%Bi3+, 5%Eu3+ phosphors had important spectral overlap with the absorption spectrum of phytochrome PR, indicating that the LGO: Bi3+, Eu3+ phosphors had great prospect to be used in indoor plant growth lighting. [Display omitted] •Bi3+/Eu3+ co-doped Lu2GeO5 phosphors were synthesized.•These phosphors showed violet-red dual emissions.•The energy transfer from Bi3+ to Eu3+ ions was investigated.•The internal quantum efficiency and thermal stability were studied.•The PL spectra of these phosphors were located within the absorption of phytochrome PR.