An Eco-Friendly Inorganic Phosphor for WLEDs of Yttrium-Doped Perovskite: A Sustainable Alternative to Toxic Lead Perovskites

Abstract

To circumvent the toxicity problem of lead, looking out for lead-free perovskites with a broadband emission and associated LEDs that cover the full region of white light is the key to research in sustainable chemistry and material community. In order to improve the luminescence properties of inorganic lead-free perovskites, chemical doping engineering is utilized. We have found that yttrium plays an important role as a dopant in broadening the emission of inorganic perovskites. This work reports on white light emission in a yttrium-doped tin perovskite and the white LED synthesized with this eco-friendly phosphor. The hue of the light can be adjusted via the change in the excitation wavelength. DFT is performed to calculate the band gaps, and a good agreement with the experimental results is illustrated. The dramatic fluorescence enhancement (by a factor of about 4.5) is also revealed on the phosphor. Based on this sustainable material, a WLED is fabricated, and a full-color white light emission is realized with a CIE of (0.32, 0.33). This work not only provides us with an inorganic phosphor for white LEDs but also demonstrates the potential of the chemical doping strategy in sustainable chemistry and materials science.