Energy transfer mediated single-component white light emission in a novel Bi3+/Eu3+ co-doped Sr2Ga2GeO7 phosphor for white LEDs

To fulfill the escalating demand for high-quality white lighting, the exploration of novel and advanced luminescent materials holds a significant role in addressing the issues of reabsorption, color bleaching and deviation in modern WLED solid-state lighting technology based on phosphor-converted materials. In this research, a series of novel Bi 3+ -activated gallium-germanate luminescent materials Sr 2 Ga 2 GeO 7 (SGGO): Bi 3+ were synthesized by means of the classic high-temperature solid-phase method. A comprehensive exploration of their crystal structure, electronic structure, and optical transition properties were conducted through a combined experimental and theoretical calculation analysis. The research outcomes suggest that Bi 3+ , which is prone to occupying Sr sites, shows a remarkable blue emission with a peak at approximately 450 nm throughout the entire spectral range from near ultraviolet (UV) to near infrared when excited at 315 nm, and this is attributed to the 3 P 1 → 1 S 0 transition. Additionally, by devising an efficient energy transfer strategy from Bi 3+ to Eu 3+ , single-component white light can be attained by merely adjusting the doping concentration of Eu 3+ in the SGGO: Bi 3+ , Eu 3+ co-activation system. Eventually, devices packaged based on 310 nm ultraviolet chips also demonstrate the potential application of the synthesized material in WLEDs. These findings contribute to a deeper understanding of the luminescence and energy transfer mechanisms of Bi 3+ -activated systems, and also offer essential guidance for the advancement of high-performance Bi 3+ -doped advanced light-conversion materials and effective materials for various applications demanding enhanced light conversion properties.