New yellowish-green light emitting thin film: 89Al2O3⋅5CeCl3⋅3EuCl3⋅3TbCl3

Abstract Aluminum oxide films doped with CeCl3, EuCl3, CeCl3/EuCl3 and CeCl3/EuCl3/TbCl3 were deposited by ultrasonic spray pyrolysis. The films were analyzed by X-ray diffraction (XRD). The XRD results revealed that the films are predominantly amorphous independent of dopants. The optical spectroscopy of these films was performed through photoluminescence spectra and decay times. Non-radiative energy transfers from Ce3+ to Tb3+ and from Ce3+ to Eu3+ take place when the films are excited at 280 nm. Excitation at 280 nm fits to the requirements of AlGaN-based LEDs. In the 89Al2O3⋅5CeCl3⋅3EuCl3⋅3TbCl3 film the simultaneous emission of the activators (Tb3+ and Eu3+) and sensitizer (Ce3+) leads to yellowish-green light emission with CIE1931 chromaticity coordinates, x = 0.32 and y = 0.52. This type of thin films might contribute to the development of AlGaN-based LEDs pumped phosphors for solid-state yellowish-green lighting.