When ZrO2 films and nanocrystals were irradiated with a 325nm laser light in an
evacuated chamber, each luminescence-intensity increases, creating a broad visible
luminescence. Then, introducing O2 gas into the specimen chamber, the
photoluminescence spectrum returns reversibly to the original luminescence under
the same laser light irradiation. After removing the laser light, each luminescence
state was stored for a long time at room temperature under room light, regardless of
any changes of atmosphere. The observed phenomena were explained by means of
the photo-induced oxygen defect creation and annihilation at/near the ZrO2 surface.
Reversible Photo-Induced Spectral Change and Defect Creation in ZrO2.
F.Fujishiro, S.Mochizuki: Physica Status Solidi C, 2009, 6[1], 354-7