Highly transparent cerium‐doped yttria ceramics for full‐band UV‐shielding window applications

Abstract Highly transparent cerium‐doped yttria ceramics were fabricated via a pressureless sintering method with an addition of 10 at.% La 2 O 3 and 1 at.% ZrO 2 as a binary sintering additive. With an increase in the Ce doping concentration from 0 to 3 at.%, the optical absorption edge of yttria ceramics exhibited a significant red shift from 290 to 380 nm as a result of the 4f–5d transition of Ce 3+ and the charge transfer of Ce 4+ (i.e., Ce 4+ +e – →Ce 3+ ). For a 2‐mm thick sample doped with 3 at.% Ce, the total ultraviolet radiation (UV) transmittance (220–400 nm) is only 1.7%, indicating a nearly complete UV absorption. Meanwhile, the specimens possess high in‐line transmittance levels in both the visible and the infrared regions (i.e., >70% at 450 nm and ∼80% at 1100 nm). Additionally, the present specimens were confirmed to have good enough mechanical strength levels (∼165 MPa) and thermal conductivity (∼5 W/m·K), which are comparable or even better compared to those of previously reported transparent yttria ceramics. The results of this work indicate that cerium‐doped transparent yttria ceramics are promising candidate materials for full‐band UV‐shielding window applications.