Cation-Deficiency-Induced Crystal-Site Engineering for ZnGa2O4:Mn2+ Thin Film

Takuro Dazai; Shintaro Yasui; Tomoyasu Taniyama; Mitsuru Itoh

doi:10.1021/acs.inorgchem.0c00359

Cation-Deficiency-Induced Crystal-Site Engineering for ZnGa₂O₄:Mn²⁺ Thin Film

Inorg Chem. 2020 Jul 6;59(13):8744-8748. doi: 10.1021/acs.inorgchem.0c00359. Epub 2020 Jun 7.

Authors

Takuro Dazai¹, Shintaro Yasui¹, Tomoyasu Taniyama^{1

2}, Mitsuru Itoh¹

Affiliations

¹ Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan.
² Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.

PMID: 32506904
DOI: 10.1021/acs.inorgchem.0c00359

Abstract

Zn-deficient spinel-type ZnGa₂O₄:Mn²⁺ phosphor thin films were prepared using pulsed laser deposition. With an increase (decrease) in the Zn deficiency (concentration) of the films, changes in lattice constant, optical band gap, and photoluminescence spectra were observed. All films without γ-Ga₂O₃:Mn showed green luminescence attributable to the transition from the ⁴T₁ state to the ⁶A₁ state. In addition, the spectral shape changed depending on the temperature. The luminescence spectra have two peaks resulting from the Mn²⁺ ions located in the tetrahedral and octahedral sites. These peaks had different thermal quenching temperatures, which were around 320 and 260 K, respectively. Therefore, the spectral shape changed with increasing temperature. The spectral shape also depended on the Zn concentration. With an increase (decrease) in the Zn concentration (deficiency) of the films, the intensity of emission from T_d increased in comparison with that from O_h. Therefore, the position of Mn²⁺ was controlled by Zn deficiency similarly to the effect of crystal-site engineering.