TY - JOUR
T1 - Similarities in photoluminescence in hafnia and zirconia induced by ultraviolet photons
AU - Ito, Toshihide
AU - Maeda, Motohiro
AU - Nakamura, Kazuhiko
AU - Kato, Hiromitsu
AU - Ohki, Yoshimichi
N1 - Funding Information:
We want to thank S. Yamazaki of National Institute of Advanced Industrial Science and Technology for providing HP samples. This work was partly done in the Joint Studies Program (2000–2004) of UVSOR Facility, Institute for Molecular Science, Okazaki, Japan and was supported by a Grant-in-Aid from Japan Society for the Promotion of Science for Scientific Research (B) Grant No. 16360160. A grant from Mizuho Foundation for the Promotion of Sciences and a High-Tech Research Grant from the Ministry of Education, Culture, Sports, Science and Technology of Japan are also appreciated.
PY - 2005
Y1 - 2005
N2 - Photoluminescence (PL) spectra induced by ultraviolet photons were measured for amorphous hafnia and zirconia deposited by plasma-enhanced chemical-vapor deposition (PECVD), amorphous hafnia deposited by pulse laser deposition, and crystalline yttria-stabilized zirconia. Two kinds of samples were prepared for both hafnia and zirconia deposited by PECVD using different source alkoxides in different deposition chambers. A PL peak was observed around 2.8 eV similarly in all hafnia and zirconia samples, irrespective of the difference in crystallinity, oxygen deficiency, source alkoxide, deposition method, or the substrate material. The decay profile of this PL is also similar in all the samples. These facts clearly show that neither impurities, oxygen vacancy, nor defects at the interface between the sample and the substrate are responsible for the PL. It is a luminescence inherent in hafnia and zirconia and is most likely due to radiative recombination between localized states at the band tails. When the samples were annealed in oxygen, a new PL peak appeared around 4.2 eV in all the amorphous samples. Its decay profile is also in common with these samples. Vacuum-ultraviolet absorption measurements and PL excitation measurements indicate that the 4.2-eV PL is excited due to the interband absorption.
AB - Photoluminescence (PL) spectra induced by ultraviolet photons were measured for amorphous hafnia and zirconia deposited by plasma-enhanced chemical-vapor deposition (PECVD), amorphous hafnia deposited by pulse laser deposition, and crystalline yttria-stabilized zirconia. Two kinds of samples were prepared for both hafnia and zirconia deposited by PECVD using different source alkoxides in different deposition chambers. A PL peak was observed around 2.8 eV similarly in all hafnia and zirconia samples, irrespective of the difference in crystallinity, oxygen deficiency, source alkoxide, deposition method, or the substrate material. The decay profile of this PL is also similar in all the samples. These facts clearly show that neither impurities, oxygen vacancy, nor defects at the interface between the sample and the substrate are responsible for the PL. It is a luminescence inherent in hafnia and zirconia and is most likely due to radiative recombination between localized states at the band tails. When the samples were annealed in oxygen, a new PL peak appeared around 4.2 eV in all the amorphous samples. Its decay profile is also in common with these samples. Vacuum-ultraviolet absorption measurements and PL excitation measurements indicate that the 4.2-eV PL is excited due to the interband absorption.
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U2 - 10.1063/1.1856220
DO - 10.1063/1.1856220
M3 - Article
AN - SCOPUS:20444478641
SN - 0021-8979
VL - 97
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 5
M1 - 054104
ER -