Efficient ultraviolet to far‐red spectral conversion: Tb3+, Cr3+ co‐doped Zn0.5Mg0.5Al2O4 phosphors and their application

Abstract Phosphor‐converted materials play a very important role in modern facility agriculture, both in converting the excess green light and low‐efficiency ultraviolet (UV) into the red and blue light that is beneficial for the plant growth, and in slowing down the aging of polymer films. In this work, UVC absorption of Zn 0.5 Mg 0.5 Al 2 O 4 (ZMAO):Cr 3+ was significantly improved by co‐doping Tb 3+ . The energy transfer (ET) from Tb 3+ to Cr 3+ occurred through a dipole–quadrupole interaction mechanism and the ET efficiency ( η ET ) from was up to 99.90% in the ZMAO:0.5%Tb 3+ , 3.0%Cr 3+ phosphor, which improved the match between the phosphor emission and absorption spectra of the phytochrome P FR . Finally, light‐conversion polymeric film is achieved by coating ZMAO:Tb 3+ , Cr 3+ phosphor. This study provides a strategy to efficiently covert the UVC and green components of the sunlight to far‐red light promoting the plant growth in horticulture and extending the service life of polymer film.