Low-temperature Photoluminescence for Polycrystalline SrZrO3 and SrHfO3

초록

We measured the temperature-dependent photoluminescence (PL) spectra of polycrystalline 4d SrZrO3 and 5d SrHfO3 synthesized by using the solid state reaction method. While the bandgap energies of both materials are higher than the light excitation energy (325 nm) we observed distinct PL signals near 1.75 eV and 2.5 eV at the lowest temperatures, which should be associated with localized states in the fairly wide bandgap. According to the literature, these peaks could be related to defect states originating from structural disorder or oxygen vacancies. The blue emission near 2.5 eV for our samples is quite similar to that observed in various 3d oxides such as SrTiO3. Interestingly, the blue emission of SrHfO3 is stronger than that of SrZrO3, which suggests that SrHfO3 could be a new optoelectronic material.

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