Thermally Stimulated Light Reflection and Photoluminescence of BaTiO3.

Perovskites have been attracting attention because of their considerable luminescence properties. A conventional perovskite such as BaTiO3 has no intrinsic photoluminescence. Doping with rare metals, nanocrystallization, and addition of organometallic halides induce significant photoluminescence and photovoltages. Here, we report anomalous light reflection and photoluminescence of BaTiO3 on heating. Light absorption shifted from the near-ultraviolet region to the visible region on heating. The small emission peaks at around 400-500 nm disappeared and new peaks appeared above 800 nm; the quantum yields of these peaks were less than 1% and more than 7%, respectively.