UV cathodoluminescence of Gd 3+ doped and Gd 3+ Pr 3+ co‐doped YAlO 3 epitaxial thin films

Thin films of YAlO 3 :Gd 3+ and YAlO 3 :Gd 3+ Pr 3+ were prepared on LaAlO 3 (001) single crystal substrates by pulsed laser deposition (PLD). Both films were grown epitaxially and their surfaces were uniformly smooth. Under UV excitation at 216 nm, YAlO 3 :Gd 3+ film did not show any intense photoluminescence (PL); on the other hand, YAlO 3 :Gd 3+ Pr 3+ film showed intense Gd 3+ PL at 314 nm through Pr 3+ 4f–5d absorption. Under electron irradiation with acceleration of 2.00 kV, both films showed UV cathodoluminescence (CL) from Gd 3+ ions. In contrast to PL, the CL intensity of the YAlO 3 :Gd 3+ film was four times greater than that of the YAlO 3 :Gd 3+ Pr 3+ film. The PL excitation spectrum of YAlO 3 :Gd 3+ in vacuum UV region revealed the presence of an intense excitation band at 155 nm assignable to YAlO 3 host absorption. This observation implied that the energy of accelerated electrons was absorbed by the host and then transferred to Gd 3+ . Pr 3+ co‐doping was found to weaken the Gd 3+ emission in CL because the excitation energy absorbed by the host was transferred to not only Gd 3+ but also Pr 3+ accompanying visible emission and nonradiative transition in Pr 3+ .