Open AccessExcitation energy dependence for electron traps in CaTiO3:Pr, Al single crystals
Author(s) -
Yasushi Nanai,
Akinori Igarashi,
Hayato Kamioka
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1220/1/012011
Subject(s) - afterglow , excited state , atomic physics , excitation , electron , photoluminescence , thermoluminescence , materials science , luminescence , physics , optoelectronics , quantum mechanics , gamma ray burst , astronomy
We investigated the red afterglow process of CaTiO 3 :Pr, Al through photoluminescence and thermoluminescence measurements by using fabricated single crystals. The crystals with several cubic millimeter in size were obtained through a flux method. We found that the afterglow properties varied with the excitation energy. At room temperature, the red afterglow was observed for the charge transfer from Pr 3+ to Ti 4+ excitation and the direct excitation of Pr 3+ , while not observed for the interband excitation of CaTiO3 due to the relaxation process going through 4d 1 5d 1 state of Pr 3+ . For the direct excitation of Pr 3+ at 80 K, the excited electrons did not reached to trap states for afterglow due to a potential barrier, which can overcome with thermal assistance at room temperature. For the charge transfer excitation at 80 K, the excited electrons could reach the traps with excess energy.