Optical and structural characterization of iron oxide and cobalt oxide thin films at 800 nm

García, Hans; Melo, Ronaldo P. de; Azevedo, A.; Araújo, Cid B. de

doi:10.1007/s00340-013-5335-3

Cited by 17 publications

(5 citation statements)

References 36 publications

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“…Based on the above XRD analyses, our CoO phase shows insulating properties with a high resistivity of 165 kΩ·cm, a low carrier concentration of 2.8 × 10 16 cm −3 , and a wide band gap of 2.8 eV, while the Co 3 O 4 phase shows semiconducting behavior with a low resistivity of 52–237 Ω·cm, a high carrier concentration of 6.8 × 10 16 –1.4 × 10 21 cm −3 , and a narrow inter band gap of 1.3–1.4 eV. The above findings are consistent with the references for CoO and Co 3 O 4 25 26 27 28 29 . In addition, increasing O 2 flow rate reflects enhanced semiconductor characteristics for the CoO x layer including an increased carrier concentration and a decreased optical band gap.…”

Section: Resultssupporting

confidence: 90%

“…In our work, CoO and Co 3 O 4 phases are created in the only Ar and Ar/O 2 mixture atmospheres, respectively. As is well-known from previous results reported by other groups, cobalt oxide typically has two stable phases: CoO and Co 3 O 4 25 26 27 . The CoO phase represents a wide optical band gaps of 2.2–2.8 eV with an insulating feature, while the Co 3 O 4 phase corresponds to narrow optical inter-band gaps of 1.4–1.5 eV and 2.18–2.23 eV with a semiconducting feature.…”

Section: Resultssupporting

confidence: 66%

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All oxide semiconductor-based bidirectional vertical p-n-p selectors for 3D stackable crossbar-array electronics

Bae

Lee

Baek

et al. 2015

Sci Rep

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Three-dimensional (3D) stackable memory devices including nano-scaled crossbar array are central for the realization of high-density non-volatile memory electronics. However, an essential sneak path issue affecting device performance in crossbar array remains a bottleneck and a grand challenge. Therefore, a suitable bidirectional selector as a two-way switch is required to facilitate a major breakthrough in the 3D crossbar array memory devices. Here, we show the excellent selectivity of all oxide p-/n-type semiconductor-based p-n-p open-based bipolar junction transistors as selectors in crossbar memory array. We report that bidirectional nonlinear characteristics of oxide p-n-p junctions can be highly enhanced by manipulating p-/n-type oxide semiconductor characteristics. We also propose an associated Zener tunneling mechanism that explains the unique features of our p-n-p selector. Our experimental findings are further extended to confirm the profound functionality of oxide p-n-p selectors integrated with several bipolar resistive switching memory elements working as storage nodes.

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Section: Resultssupporting

confidence: 90%

Section: Resultssupporting

confidence: 66%

All oxide semiconductor-based bidirectional vertical p-n-p selectors for 3D stackable crossbar-array electronics

Bae

Lee

Baek

et al. 2015

Sci Rep

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“…Refractive index values and dispersion are given on figure 9. Garcia et al [36] have found the refractive index of Co3O4 to be 2.48 at 633 nm. This is very similar to our result, however…”

Section: Film Growth and Compositionmentioning

confidence: 99%

Electrical and magnetic properties of atomic layer deposited cobalt oxide and zirconium oxide nanolaminates

et al. 2019

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Introduction Nanostructured Co3O4 in thin film form may possess and demonstrate a variety of properties making the material attractive for several applications. Co3O4 has been investigated as an important electrode material [1-4], gas sensor [5, 6], catalyst [7, 8], or superhydrophobic coating [9]. Co3O4 films have demonstrated resistive switching properties potentially enabling their application in resistive random access memory devices [10, 11]. Cobalt oxide, Co3O4, containing Co 2+ and Co 3+ ions, is recognized as magnetic semiconductor material [12]. Antiferromagnetic behavior with characteristic magnetization-field curves can be demonstrated by Co3O4 nanoparticles [13]. Regarding the possible applications in spintronics, it may occur necessary to activate ferromagnetic coupling in Co3O4 nanoparticles by hybridization with foreign materials, e.g. graphene oxide [14]. Co3O4 films have been grown by oxidation of electron-beam evaporated Co layers [15], pulsed laser deposition [5, 10] chemical bath deposition [1, 6], chemical solution deposition [8, 11], hydrothermal method [2, 13], solvothermal synthesis [9], spray pyrolysis [16]

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“…When Co 3 O 4 is added to chromium oxide (Cr 2 O 3 ), a conductive network is created through the pores . Among the oxides family, Co 3 O 4 is one of the multilateral oxide sided, it has properties similar to a p‐type semiconductor, and the band gap ranges from 2.23 to 3.38 eV . Co 3 O 4 has attracted exceptional attention in the domain of application technology for pigments and solar‐selective surfaces .…”

Section: Introductionmentioning

confidence: 99%

Spectrally selective coating of nanoparticles (Co₃O₄:Cr₂O₃) incorporated in carbon to captivate solar energy

et al. 2020

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Innovatory nanocomposite comprising nanomaterials Co 3 O 4 :Cr 2 O 3 and carbon (fuel ash) was designed to absorb solar energy. Different concentration ratios of Co 3 O 4 and Cr 2 O 3 nanoparticles were utilized as a dopant for fuel thin films synthesis via spin and casting methods on glass and aluminum substrates. The opticalproperties of the modified films demonstrated in the range of 250 to 1300 nm. The data were interpreted in terms of a phonon-assisted theory. Energy gap (E g ) of doped C was calculated with different concentration ratios of Co 3 O 4 :Cr 2 O 3 (0.5:2.5, 1:2, 1.5:1.5, 2:1, 2.5:0.5) wt%, and fixed concentration of C in 7wt%. The results showed E g of the doped samples in the range of 2.9 to 3.9 eV. In addition, the intensity of the solar radiation was measured. The absorptivity was in the range of 88 to 93.6%. The above results are comparable to those of semiconductors and have high absorptivity values when the nanocomposite was utilized on a flat plate collector as a coating to trap and absorb solar energy. K E Y W O R D S chromium oxide, cobalt oxide, emissivity and absorptivity, energy band gap, optical properties 1 | INTRODUCTIONGenerally, Iraq has 240 days of strong sunlight with energy of 5 kWh per square meter in a day. 1 Harvesting solar energy and utilizing it in domestic applications, such as heating the water or ventilation residential complexes, would be highly cost effective and environment friendly. Nanocomposite films are used for this purpose. The technology includes the use of the nanocomposite films as a coating on a flat plate collector to be spectrally selective surface. This surface has low emissivity and high absorptivity to solar energy to convert this solar light into heat. 1,2 Doping nanomaterials with carbon can cause a remarkable change to its optical properties. [3][4][5] Cobalt oxide (Co 3 O 4 ) is a prevalent factor having several oxidization states because of its unusual chemical and physical features. It is used in ceramics production as an additional factor to produce blue coloring glazes, photo-catalysis, 6-10 and absorbance energy storage. 5,11 Further, Co 3 O 4 does has significant electrical properties. When Co 3 O 4 is added to chromium oxide (Cr 2 O 3 ), a conductive network is created through the pores. 12-15 Among the oxides family, Co 3 O 4 is one of the multilateral oxide sided, it has properties similar to a p-type semiconductor, and the band gap ranges from 2.23 to 3.38 eV. 16,17 Co 3 O 4 has attracted exceptional attention in the domain of application technology for pigments and solar-selective surfaces. [18][19][20] The particle size of Co 3 O 4 for nano-or micro-size provides perfect performance for electrochemical of different ranges in electronic applications and solar energy coating. [21][22][23][24] Nanocrystalline thin films nickel-cobalt oxides (NiO-CoO) were deposited on steel and glass substrates to produce thin films of different concentrations by the chemical bath deposition (CBD) method. These thin films exhibited semiconductor feature...

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Optical and structural characterization of iron oxide and cobalt oxide thin films at 800 nm

Cited by 17 publications

References 36 publications

All oxide semiconductor-based bidirectional vertical p-n-p selectors for 3D stackable crossbar-array electronics

All oxide semiconductor-based bidirectional vertical p-n-p selectors for 3D stackable crossbar-array electronics

Electrical and magnetic properties of atomic layer deposited cobalt oxide and zirconium oxide nanolaminates

Spectrally selective coating of nanoparticles (Co₃O₄:Cr₂O₃) incorporated in carbon to captivate solar energy

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Optical and structural characterization of iron oxide and cobalt oxide thin films at 800 nm

Cited by 17 publications

References 36 publications

All oxide semiconductor-based bidirectional vertical p-n-p selectors for 3D stackable crossbar-array electronics

All oxide semiconductor-based bidirectional vertical p-n-p selectors for 3D stackable crossbar-array electronics

Electrical and magnetic properties of atomic layer deposited cobalt oxide and zirconium oxide nanolaminates

Spectrally selective coating of nanoparticles (Co3O4:Cr2O3) incorporated in carbon to captivate solar energy

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Spectrally selective coating of nanoparticles (Co₃O₄:Cr₂O₃) incorporated in carbon to captivate solar energy