Investigation of Oxygen Vacancy and Interstitial Oxygen Defects in ZnO Films by Photoluminescence and X-Ray Photoelectron Spectroscopy

Fan, Hongwei; Yang, Shuangqiao; Zhang, Panfeng; Wei, Hongyuan; Liu, Xianglin; Jiao, Chunlei; Zhu, Qinsheng; Chen, Yonghai; Wang, Zhanguo

doi:10.1088/0256-307x/24/7/089

Cited by 199 publications

(55 citation statements)

References 17 publications

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“…The spectrum revealed a peak at 3.28 eV related with band-edge emission [18]. As a matter of fact, the intensity of band-edge emission is directly related with the quality of grown film [19]. Most of the oxygen vacancy related defects are compensated with incoming oxygen as the annealing temperature increases from 500 to 800…”

Section: Pl Measurementsmentioning

confidence: 99%

Investigation of V_O–Zn_inative donor complex in MBE grown bulk ZnO

Asghar

Kazemzad

Ferguson

et al. 2013

Semicond. Sci. Technol.

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In this paper, we have experimentally investigated the theoretical predictions of V O -Zn i to be a native donor in ZnO. Intrinsically zinc-rich n-type ZnO thin films having N D ∼ 6.23 × 10 18 cm −3 grown by molecular beam epitaxy on Si (0 0 1) substrate were annealed in oxygen environment at 500-800• C, keeping a step of 100• C for 1 h, each. Room temperature Hall measurements demonstrated that free donor (V O -Zn i ) concentration decreased exponentially and Arrhenius plot yielded activation energy to be 1.2 ± 0.01 eV. This value is in agreement with theoretically reported activation energy of V O -Zn i donor complex in ZnO. We argue; this observation can be explained by two-step process: (i) incoming oxygen fills V O of V O -Zn i complex leaving behind Zn i ; (ii) Zn i releases its energy and moves to a lower energy state with respect to the conduction band minima and/or occupies an inactive location. Consequently, Zn i -V O complex loses its donor role in the lattice. Our experimental data supported theoretical predictions of V O -Zn i to be a native donor. Results from photoluminescence spectroscopy carried out on Zn-rich ZnO additionally justify the existence of V O -Zn i complex.

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Section: Pl Measurementsmentioning

confidence: 99%

Investigation of V_O–Zn_inative donor complex in MBE grown bulk ZnO

Asghar

Kazemzad

Ferguson

et al. 2013

Semicond. Sci. Technol.

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“…The effect of annealing on the native defects of ZnO has been studied extensively and it has been demonstrated that the crystallinity of ZnO can be improved by annealing the samples at higher temperatures, typically above 500 °C [16–20]. However, some studies show that annealing at higher temperatures can also introduce defects, such as oxygen interstitials in the ZnO lattice [21–22]. …”

Section: Introductionmentioning

confidence: 99%

Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin

Bora¹,

Lakshman²,

Sarkar³

et al. 2013

Beilstein J. Nanotechnol.

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SummaryIn recent years, nanotechnology has gained significant interest for applications in the medical field. In this regard, a utilization of the ZnO nanoparticles for the efficient degradation of bilirubin (BR) through photocatalysis was explored. BR is a water insoluble byproduct of the heme catabolism that can cause jaundice when its excretion is impaired. The photocatalytic degradation of BR activated by ZnO nanoparticles through a non-radiative energy transfer pathway can be influenced by the surface defect-states (mainly the oxygen vacancies) of the catalyst nanoparticles. These were modulated by applying a simple annealing in an oxygen-rich atmosphere. The mechanism of the energy transfer process between the ZnO nanoparticles and the BR molecules adsorbed at the surface was studied by using steady-state and picosecond-resolved fluorescence spectroscopy. A correlation of photocatalytic degradation and time-correlated single photon counting studies revealed that the defect-engineered ZnO nanoparticles that were obtained through post-annealing treatments led to an efficient decomposition of BR molecules that was enabled by Förster resonance energy transfer.

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“…Using XPS, we were able to identify both oxygen vacancies [17,70,71] and adsorbed water [72][73][74] on the surface of the catalyst as seen from the O1s peak of our photocatalyst after the photomethanation test ( Figure S8, Supporting Information). Then CO 2 interacts with hydroxyl groups to form intermediates such as formates, carbonates, and bicarbonates, which lead to the final methane product.…”

Section: Resultsmentioning

confidence: 99%

Highly Efficient Ambient Temperature CO₂ Photomethanation Catalyzed by Nanostructured RuO₂ on Silicon Photonic Crystal Support

Jelle

Ghuman

O’Brien

et al. 2018

Advanced Energy Materials

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Sunlight‐driven catalytic hydrogenation of CO2 is an important reaction that generates useful chemicals and fuels and if operated at industrial scales can decrease greenhouse gas CO2 emissions into the atmosphere. In this work, the photomethanation of CO2 over highly dispersed nanostructured RuO2 catalysts on 3D silicon photonic crystal supports, achieving impressive conversion rates as high as 4.4 mmol gcat−1 h−1 at ambient temperatures under high‐intensity solar simulated irradiation, is reported. This performance is an order of magnitude greater than photomethanation rates achieved over control samples made of nanostructured RuO2 on silicon wafers. The high absorption and unique light‐harvesting properties of the silicon photonic crystal across the entire solar spectral wavelength range coupled with its large surface area are proposed to be responsible for the high methanation rates of the RuO2 photocatalyst. A density functional theory study on the reaction of CO2 with H2 revealed that H2 splits on the surface of the RuO2 to form hydroxyl groups that participate in the overall photomethanation process.

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Investigation of Oxygen Vacancy and Interstitial Oxygen Defects in ZnO Films by Photoluminescence and X-Ray Photoelectron Spectroscopy

Cited by 199 publications

References 17 publications

Investigation of V_O–Zn_inative donor complex in MBE grown bulk ZnO

Investigation of V_O–Zn_inative donor complex in MBE grown bulk ZnO

Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin

Highly Efficient Ambient Temperature CO₂ Photomethanation Catalyzed by Nanostructured RuO₂ on Silicon Photonic Crystal Support

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Investigation of Oxygen Vacancy and Interstitial Oxygen Defects in ZnO Films by Photoluminescence and X-Ray Photoelectron Spectroscopy

Cited by 199 publications

References 17 publications

Investigation of VO–Zninative donor complex in MBE grown bulk ZnO

Investigation of VO–Zninative donor complex in MBE grown bulk ZnO

Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin

Highly Efficient Ambient Temperature CO2 Photomethanation Catalyzed by Nanostructured RuO2 on Silicon Photonic Crystal Support

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Product

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Investigation of V_O–Zn_inative donor complex in MBE grown bulk ZnO

Investigation of V_O–Zn_inative donor complex in MBE grown bulk ZnO

Highly Efficient Ambient Temperature CO₂ Photomethanation Catalyzed by Nanostructured RuO₂ on Silicon Photonic Crystal Support