Abstract
We studied electron carrier doping into the ternary wurtzite β-AgGaO2 by impurity doping. Ti-doped β-NaGaO2, i.e., β-Na(Ga1−xTix)O2, was prepared by a conventional high-temperature solid-state reaction; then, we performed ion-exchange of Na+ ions with Ag+ ions into the Ti-doped β-NaGaO2 in a molten nitrate salt to produce Ti-doped β-AgGaO2: β-Ag(Ga1−xTix)O2. A single ternary wurtzite phase was obtained at compositions of 0≤x≤0.05. Ti-doped β-AgGaO2 showed an electrical conductivity at room temperature that was one to three orders of magnitude higher than that of undoped β-AgGaO2. The Ti-doped β-AgGaO2 samples showed an electron carrier density in the range of 1018−1019 cm−3, based on the free-carrier absorption shown in their optical absorption spectra. These results show that carrier injection by impurity doping into metastable β-CuMIIIO2 and β-AgMIIIO2 is possible by using an impurity-doped β-NaGaO2 precursor. This result encourages the development of optoelectronic devices based on the narrow-band-gap oxide semiconductors of β-CuMIIIO2 and β-AgMIIIO2.
Highlights
Oxides are safe and environmentally conscious materials—they are generally stable in ambient atmosphere and water, and oxygen is earth-abundant and much safer than chalcogens, such as sulfur and selenium, and pnictogens, such as arsenic and antimony—which should lead to broad use
For x=0.07, very small but clear diffraction peaks arising from γ-NaGaO2 and an unknown phase appeared. These results indicate that Ti dissolved into the Ga site of β-NaGaO2 and that a single phase of wurtzite β-Na(Ga1−xTix)O2 appeared for 0≤x≤0.05. β-Na(Ga1−xTix)O2 with x=0, 0.01, 0.03, and 0.05 were subjected to ion-exchange of Na+ ions with Ag+ ions
The Ti-doped samples showed broad absorption in the near-infrared (NIR) region of λ>650 nm in addition to the fundamental absorption. Such broad absorption in the NIR region usually appears in oxide semiconductors with injected electron carriers, such as Al-doped ZnO,[18,19] Sn-doped In2O3,20 and F-doped SnO2,21 and this absorption is attributed to free-carrier absorption arising from plasma oscillations of electron carriers
Summary
Oxides are safe and environmentally conscious materials—they are generally stable in ambient atmosphere and water, and oxygen is earth-abundant and much safer than chalcogens, such as sulfur and selenium, and pnictogens, such as arsenic and antimony—which should lead to broad use. To produce Al2O3-doped ZnO, Al atoms dissolve into the Zn site in ZnO by the high-temperature solid-state reaction shown in equation (1), and the Al atoms act as donors to inject conduction electrons. Β-CuMIIIO2 and β-AgMIIIO2 are produced via ion-exchange of Na+ ions in a ternary wurtzite β-NaMIIIO2 precursor with Cu+ or Ag+ ions at
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
