Band gap of LiInO
            <sub>2</sub>
            synthesized by a sol–gel method

Kushida, K.; Kuriyama, K.

doi:10.1002/pssc.200669516

Cited by 6 publications

(3 citation statements)

References 12 publications

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“…10 The solid solubility limit of Eu 3+ in this host lattice is x = 0.1; beyond this Eu 2 O 3 impurity is observed. Figure 2 shows 11,12 From the reported energy dispersion diagram and density of states of LiInO 2 , the valence band is found to be a combination of O 2p orbitals. The upper part of the conduction band was formed by the hybridized Li 2s and 2p orbitals, whereas the lower part of conduction band consists of In 5s and 5p orbitals.…”

Section: Resultsmentioning

confidence: 95%

Electric Dipole Red Emission in Eu[sup 3+]-Doped Low Bandgap Oxide LiInO[sub 2]

Naidu

Varadaraju

2008

Electrochem. Solid-State Lett.

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Eu 3+ -doped LiInO 2 phosphors have been synthesized by solid-state reaction at 1000°C and characterized by powder X-ray diffraction and photoluminescence studies. These phosphors show emission lines of Eu 3+ corresponding to 5 D 0 -7 F J ͑J = 1,2͒ transitions under 466 nm excitation. Among these emission transitions, the 5 D 0 -7 F 2 electric dipole transition at 614 nm is the predominant one. The critical concentration of Eu 3+ is x = 0.05 in LiIn 1−x Eu x O 2 , beyond which concentration quenching is observed. The emission intensity of LiIn 0.95 Eu 0.05 O 2 phosphor is ϳ1.3 times that of Y 2 O 2 S:Eu 3+ ͑Nichia͒.A large number of Eu 3+ activated phosphors have drawn considerable attention in view of their application as red phosphors in color television tubes and field emission displays. For these applications, phosphors exhibiting pure red emission with a high efficiency are required. Knowledge of the factors influencing the efficiency of phosphors is limited. For example, the phosphors Gd 2 O 3 :Eu 3+ and YVO 4 :Eu 3+ are highly efficient 1,2 and the phosphors Gd 2 Ti 2 O 7 :Eu 3+ and Y 2 MoO 6 :Eu 3+ are less efficient. Eu 3+ red emission depends on strong distortions in the host lattice. The intensity of the 5 D 0 -7 F 2 ͑red emission͒ transition varies when the polarization of the surrounding anion changes by crystal chemical substitutions in the host lattice; this has been observed in various garnets. 3 The difference in energy between the ground and excited states in Eu 3+ is typically ϳ3.2 eV; therefore, large bandgap oxides are required as hosts for incorporation of Eu 3+ and to obtain reasonable emission intensities.Phosphors with a low bandgap host are needed for application in field emission displays ͑FEDs͒ to minimize charging effects. Y 2 O 2 S:Eu 3+ red phosphor is presently used in FEDs; it can be considered as a wide bandgap semiconductor ͑E g = 4.6-4.8 eV͒. 4,5 Blasse and Bril have studied a series of Eu 3+ containing mixed metal oxides with rock salt-type structure and observed that, when excited with 250-270 nm wavelength radiation, both LiIn 0.95 Eu 0.05 O 2 and NaIn 0.95 Eu 0.05 O 2 have a low quantum efficiency. 6 Recently, the phosphors SrIn 2 O 4 ͑E g = 3.6 eV͒: Pr 3+ , Tb 3+ , and CaIn 2 O 4 ͑E g = 3.9 eV͒: Pr 3+ , Tb 3+ have been studied as possible candidates for application in FEDs. 7,8 The electric dipole transition of Eu 3+ is the ideal choice for red emission; the challenge is to find host lattices with a low bandgap which can give rise to reasonable intensities for the Eu 3+ emission. Thus, it is of interest to search for materials with an optimum bandgap ͑the lowest possible͒ which can give rise to a reasonable emission intensity of Eu 3+ . In our endeavor to explore phosphor materials satisfying the above criteria, we have synthesized and studied a series of Eu 3+ -doped LiInO 2 compounds and shown that LiIn 0.95 Eu 0.05 O 2 is a promising phosphor. ExperimentalLiIn 1−x Eu x O 2 ͑x = 0.01-0.07, in steps of 0.02 and x = 0.1͒ and NaIn 0.95 Eu 0.05 O 2 and NaLa 0.95 Eu 0.05 O 2 ...

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Section: Resultsmentioning

confidence: 95%

Electric Dipole Red Emission in Eu[sup 3+]-Doped Low Bandgap Oxide LiInO[sub 2]

Naidu

Varadaraju

2008

Electrochem. Solid-State Lett.

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“…which is the same as previously reported. [45] The optical transmittance spectra and Tauc's plot of LiGaO 2 thin films are given in Figure S6 which looks very similar to nature with LiInO 2 . However, the extracted band gap of LiGaO 2 is 5.5 eV which is much higher than LiInO 2 thin film.…”

Section: Optical Properties Of Lilno 2 Thin Filmsmentioning

confidence: 74%

Dielectric/Semiconductor Interfacial p‐Doping: A New Technique to Fabricate Solution‐Processed High‐Performance 1 V Ambipolar Oxide Transistors

Chourasia

Sharma

Pal

et al. 2020

Physica Rapid Research Ltrs

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Complementary metal-oxide-semiconductor (CMOS) technology is used prevalently for constructing different integrated circuits in microprocessors, microcontrollers, static RAM, image sensors, data converters, and highly integrated transceivers in various types of communications. [1] An ambipolar thin-film transistor (TFT) provides both electron and hole conduction in a single TFT, which is a unique choice for high-density CMOS fabrication. [2] In addition to this CMOS fabrication, ambipolar charge transport of TFTs is widely used for developing lightemitting transistors, [3] flash memories, [4] and artificial synaptic emulation. [5] To date, most reported thin-film ambipolar transistors have been fabricated by using small organic molecule and polymer semiconductors. [6,7] However, the main difficulties of these organic small-molecule/polymerbased TFTs are their low carrier mobility and poor atmospheric stability for electron transport. [2] In contrast, low-cost solutionprocessed metal-oxide-semiconductors exhibit relatively excellent environmental stability and higher carrier mobility. Moreover, the operating voltage of metaloxide TFTs can be reduced to 2.0 V by using a high-κ gate dielectric, such as Ta 2 O 5 , [7] ZrO 2 ,or [8] HfO x. [9] Therefore, it is of utmost importance to develop highperformance, low-operating-voltage, oxide ambipolar TFTs by a solution-processed technique. To date, ion-conducting oxide dielectrics show the best performance in lowering the operating voltage of oxide TFTs due to their high capacitance value, which originates from the mobile ion of the dielectric thin film. [10,11] However, the main obstacle is to find out a high-performance hole transport metal-oxide-semiconductor. [12] So far, SnO and SnO 2 have shown some potential. [13] Similar to various metaloxide-semiconductors, tin oxide (SnO 2) is commonly found as an n-type semiconductor. However, the p-type SnO 2 could be formed by introducing a hole carrier in its valence band. Until now, there are two established methods to achieve this hole transport phenomenon in SnO 2 semiconductors. One of them is performed by creating Sn vacancies, which can introduce a hole carrier to the valence band of SnO 2 , commonly attained by controlled sputtering method deposition. [14] The other way is by chemical doping with group IIIA elements such as indium (In) and gallium (Ga), which can occupy an Sn site in the SnO 2 lattice. [15] Based on those earlier reports, we have fabricated a SnO 2 TFT by choosing LiInO 2 and LiGaO 2 as ion-conducting oxide dielectrics, which can dope In and Ga atoms, respectively, to the interfacial layer of SnO 2. To identify the differences, we have also chosen Li 2 ZnO 2 as a third ionic dielectric containing a divalent Zn atom, which is unable to introduce holes in SnO 2. A comparative electrical characterization shows a clear n-channel

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“…Photoacoustic spectroscopy (PAS) is a useful tool for studying optical absorption spectra of light scattering materials such as powders and polycrystalline samples [2,3,8,9]. PAS is also expected to be applicable to the study of nonradiative process in excited solids, since the photoacoustic (PA) signal seems to be related to the nonradiative part of de-excitation or recombination.…”

Section: Band Gap Evaluation By Photoacoustic Spectroscopymentioning

confidence: 99%