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ZnO-porous silicon nanocomposite for possible memristive device fabrication.

Martínez L, Ocampo O, Kumar Y, Agarwal V - Nanoscale Res Lett (2014)

Bottom Line: Preliminary results on the fabrication of a memristive device made of zinc oxide (ZnO) over a mesoporous silicon substrate have been reported.Porous silicon (PS) substrate is employed as a template to increase the formation of oxygen vacancies in the ZnO layer and promote suitable grain size conditions for memristance.The proposed device exhibits a zero-crossing pinched hysteresis current-voltage (I-V) curve characteristic of memristive systems.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Engineering and Applied Sciences (CIICAp-UAEM), Av. Universidad 1001. Col. Chamilpa, Cuernavaca, Morelos 62209, Mexico.

ABSTRACT
Preliminary results on the fabrication of a memristive device made of zinc oxide (ZnO) over a mesoporous silicon substrate have been reported. Porous silicon (PS) substrate is employed as a template to increase the formation of oxygen vacancies in the ZnO layer and promote suitable grain size conditions for memristance. Morphological and optical properties are investigated using scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. The proposed device exhibits a zero-crossing pinched hysteresis current-voltage (I-V) curve characteristic of memristive systems.

No MeSH data available.


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Photoluminescence spectra of porous silicon substrate (S1) and PS-ZnO composites before (ZS1) and after (ZS1-A) annealing at 700°C.
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Figure 3: Photoluminescence spectra of porous silicon substrate (S1) and PS-ZnO composites before (ZS1) and after (ZS1-A) annealing at 700°C.

Mentions: PL spectra of PS and ZnO/PS structures are shown in Figure 3. The PL spectrum of the sample ZS1 (corresponding to the ZnO/PS structure before annealing) shows emission in the UV region around 372 nm, characteristic of the near-band edge excitonic recombinations in the ZnO film [21]. The PL emission in the visible region could be attributed to the radiative recombination of the delocalized electron close to the conduction band with a deeply trapped hole in the zinc and oxygen vacancies (VZn−, Vo+) and oxygen centers (Oi), respectively [21]. After annealing, the emission from the composite (ZS1-A) enhances in the UV region accompanied with a decrease in the visible range. The emission in the visible region is mainly due to deep-level defects (such as oxygen vacancies). The ratio of UV to visible emission has been considered as a key criterion to evaluate the crystalline quality. Consequently, a strong UV emission and weak green emission from ZnO could be attributed to the good crystalline quality of the ZnO film which is not the case before annealing. The deep-level emission is usually related to structural defects and impurities; however, the structural defects depend on lattice mismatch [24]. The PL emission band around 531 nm (2.3 eV) is associated with the radiative recombination of photogenerated holes with single ionized charge of specific defects such as oxygen vacancies or Zn interstitials [25-27].


ZnO-porous silicon nanocomposite for possible memristive device fabrication.

Martínez L, Ocampo O, Kumar Y, Agarwal V - Nanoscale Res Lett (2014)

Photoluminescence spectra of porous silicon substrate (S1) and PS-ZnO composites before (ZS1) and after (ZS1-A) annealing at 700°C.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150548&req=5

Figure 3: Photoluminescence spectra of porous silicon substrate (S1) and PS-ZnO composites before (ZS1) and after (ZS1-A) annealing at 700°C.
Mentions: PL spectra of PS and ZnO/PS structures are shown in Figure 3. The PL spectrum of the sample ZS1 (corresponding to the ZnO/PS structure before annealing) shows emission in the UV region around 372 nm, characteristic of the near-band edge excitonic recombinations in the ZnO film [21]. The PL emission in the visible region could be attributed to the radiative recombination of the delocalized electron close to the conduction band with a deeply trapped hole in the zinc and oxygen vacancies (VZn−, Vo+) and oxygen centers (Oi), respectively [21]. After annealing, the emission from the composite (ZS1-A) enhances in the UV region accompanied with a decrease in the visible range. The emission in the visible region is mainly due to deep-level defects (such as oxygen vacancies). The ratio of UV to visible emission has been considered as a key criterion to evaluate the crystalline quality. Consequently, a strong UV emission and weak green emission from ZnO could be attributed to the good crystalline quality of the ZnO film which is not the case before annealing. The deep-level emission is usually related to structural defects and impurities; however, the structural defects depend on lattice mismatch [24]. The PL emission band around 531 nm (2.3 eV) is associated with the radiative recombination of photogenerated holes with single ionized charge of specific defects such as oxygen vacancies or Zn interstitials [25-27].

Bottom Line: Preliminary results on the fabrication of a memristive device made of zinc oxide (ZnO) over a mesoporous silicon substrate have been reported.Porous silicon (PS) substrate is employed as a template to increase the formation of oxygen vacancies in the ZnO layer and promote suitable grain size conditions for memristance.The proposed device exhibits a zero-crossing pinched hysteresis current-voltage (I-V) curve characteristic of memristive systems.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Engineering and Applied Sciences (CIICAp-UAEM), Av. Universidad 1001. Col. Chamilpa, Cuernavaca, Morelos 62209, Mexico.

ABSTRACT
Preliminary results on the fabrication of a memristive device made of zinc oxide (ZnO) over a mesoporous silicon substrate have been reported. Porous silicon (PS) substrate is employed as a template to increase the formation of oxygen vacancies in the ZnO layer and promote suitable grain size conditions for memristance. Morphological and optical properties are investigated using scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. The proposed device exhibits a zero-crossing pinched hysteresis current-voltage (I-V) curve characteristic of memristive systems.

No MeSH data available.


Related in: MedlinePlus