Perovskite fluoride crystals as light emitting materials in vacuum ultraviolet region

摘要

Vacuum-ultraviolet (VUV) fluorescence from KMgF_3 and BaLiF_3 crystals excited by an extreme ultraviolet free electron laser (EUV-FEL) with 61-nm emission wavelength is studied. Cross-luminescence (CL) peaks at 8.5 eV and 7.5 eV, due to an electron from the valence band recombining with a hole in the F2p core band edge are observed in KMgF_3. On the other hand, BaLiF_3 exhibited a fluorescence peak at 7.75 eV. The band gap energy of BaLiF_3 is estimated from its absorption spectrum to be around 8.41 eV. Results suggest the possibility of developing VUV solid-state devices including light emitting diodes.