Chemical vapor deposition route to transparent thick films of Eu3+-doped HfO2 and Lu2O3 for luminescent phosphors

Crystal growth from the vapor phase is an alternative to melt solidification and sintering for fabricating optical materials with high melting points and reversible phase transformations. We demonstrated the rapid synthesis of transparent thick films of Eu-doped monoclinic HfO2 (Eu3+:HfO2) and cubic Lu2O3 (Eu3+:Lu2O3) using laser-assisted metal–organic chemical vapor deposition. The transparent single-crystalline films were epitaxially grown on yttria-stabilized zirconia substrates at the deposition rates of 15–20 µm h−1. Under irradiation by ultraviolet light, the Eu3+:HfO2 and Eu3+:Lu2O3 transparent thick films exhibited intense red emissions at 614–615 nm corresponding to the 5D0 → 7F2 transitions of the Eu3+ ions located in asymmetric environments.