Application of channeling-enhanced electron energy-loss spectroscopy for polarity determination in ZnO nanopillars

Jasiński, Jacek B.; Zhang, D.; Parra, J.; Katkanant, V.; Leppert, Valerie J.

doi:10.1063/1.2889496

Cited by 25 publications

(14 citation statements)

References 25 publications

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“…Overall, the issue of polarity in the field of ZnO nanostructures have been reported depending on the polarity of the ZnO nucleation surface ,,,,− and investigated regarding their polarity itself. The physical and chemical vapor deposition techniques typically results in the formation of Zn-polar ZnO NRs ,,,− or nanostructures following the catalyst-free or self-induced approaches, , regardless of the polarity of the nucleation surface. Even on O-polar ZnO nucleation surfaces, extended defects like inversion domain boundaries are commonly formed to reverse the polarity of ZnO NRs in favor of the Zn-polarity, owing to aluminum surfactant effects. , In contrast, Consonni et al recently showed that O-polar ZnO NRs can be formed by using CBD and that their structural uniformity can thoroughly be controlled on patterned ZnO single crystals by electron beam lithography (EBL) .…”

Section: Introductionmentioning

confidence: 99%

Polarity-Dependent Growth Rates of Selective Area Grown ZnO Nanorods by Chemical Bath Deposition

et al. 2017

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Polarity is known to affect the growth and properties of ZnO single crystals and epitaxial films, but its effects are mostly unknown in ZnO nanorods. To leave polarity as the only varying parameter, ZnO nanorods are grown by chemical bath deposition under identical conditions and during the same run on O- and Zn-polar ZnO single crystals patterned by electron beam lithography with the same pattern consisting of 15 different domains. The resulting well-ordered O- and Zn-polar ZnO nanorod arrays with high structural uniformity are formed on all the domains. The comparison of their typical dimensions unambiguously reveals that Zn-polar ZnO nanorods have much higher growth rates than O-polar ZnO nanorods for all the hole diameter and period combinations. The distinct growth rates are explained in the framework of the surface reaction-/diffusive transport-limited elongation regime analysis, which yields a much larger surface reaction rate constant for Zn-polar ZnO nanorods. The origin of the difference is attributed to polarity-dependent dangling bond configurations at the top polar c-faces of ZnO nanorods, which may further be affected by polarity-dependent interactions with the ionic species in aqueous solution. These findings show the relevance of considering polarity as an important quantity in ZnO nanorods.

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Section: Introductionmentioning

confidence: 99%

Polarity-Dependent Growth Rates of Selective Area Grown ZnO Nanorods by Chemical Bath Deposition

et al. 2017

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“…Finally, we devote the final section of the present work to illustrate possible polarity inversions in nanostructured semiconductor materials, discussing a few examples of inversion boundaries, which eventually allow a smart manifold functionalization of the Polarity-Driven Growth of Vertical Nanowires. While semiconductor NWs have extensively been studied systems over 48 Poole et al, 49 Gao et al 50 → SAG B (P) Algra et al, 51 Dalacu et al, 52 Calahorra et al 53 → particle-assisted GaN A (Ga) Schuster et al, 33 Bengoechea-Encabo et al 54 → SAG B (N) Fernańdez-Garrido et al, 55 Bertness et al, 56 Schuster et al 57 → particle-assisted Muβëner et al 58 → spontaneous growth InN A (In) Wang et al 59 → spontaneous growth B (N) Stoica et al, 60 Chang et al, 61 Wang et al 59 → spontaneous growth ZnO A (Zn) Baxter et al, 62 Sallet et al, 63 Utama et al, 64 Guillemin et al, 65 Sun et al, 66 Nicholls et al 67 → spontaneous growth Scrymgeour et al, 68 Perillat-Merceroz et al, 69 Consonni et al 70 → SAG Jasinski et al 71 → particle-assisted B (O) Guillemin et al 72 → spontaneous growth Consonni et al 70 → SAG Sallet et al 63 → particle-assisted Figure 3. Intrinsic parameters of the binary compounds analyzed, such as the ratio between the constituent sizes (r b /r a ), including the cases of ionic (a), covalent (b), and atomic radius, and the ionic character of the compound showing the electronegativity for each constituent, χ, along with the difference in electronegativity for every considered compound (d), calculated following Pauling's expression (more details provided in the Supporting Information).…”

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confidence: 99%

The Role of Polarity in Nonplanar Semiconductor Nanostructures

et al. 2019

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The lack of mirror symmetry in binary semiconductor compounds turns them into polar materials, where two opposite orientations of the same crystallographic direction are possible. Interestingly, their physical properties (e.g., electronic or photonic) and morphological features (e.g., shape, growth direction, and so forth) also strongly depend on the polarity. It has been observed that nanoscale materials tend to grow with a specific polarity, which can eventually be reversed for very specific growth conditions. In addition, polar-directed growth affects the defect density and topology and might induce eventually the formation of undesirable polarity inversion domains in the nanostructure, which in turn will affect the photonic and electronic final device performance. Here, we present a review on the polarity-driven growth mechanism at the nanoscale, combining our latest investigation with an overview of the available literature highlighting suitable future possibilities of polarity engineering of semiconductor nanostructures. The present study has been extended over a wide range of semiconductor compounds, covering the most commonly synthesized III−V (GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb) and II−VI (ZnO, ZnTe, CdS, CdSe, CdTe) nanowires and other free-standing nanostructures (tripods, tetrapods, belts, and membranes). This systematic study allowed us to explore the parameters that may induce polarity-dependent and polaritydriven growth mechanisms, as well as the polarity-related consequences on the physical properties of the nanostructures.

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“…The crystallographic polarity can be determined using several methods, including low-energy electron diffraction (LEED), reflection high-energy electron diffraction (RHEED), X-ray diffraction (XRD), , X-ray photoelectron diffraction (XPD), convergent beam electron diffraction, , Auger electron spectroscopy, , and electron energy-loss spectroscopy . None of these methods, however, can be employed to determine the surface polarity of SiC; because they characterize SiC through interactions between incident electrons and a long-range-ordered atomic arrangement of the substrate, they cannot be used to analyze only the surface layer of the SiC wafers.…”

Section: Introductionmentioning

confidence: 99%

Using Visible Laser-Based Raman Spectroscopy to Identify the Surface Polarity of Silicon Carbide

et al. 2016

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In this study we developed an approach to identify the surface polarity of silicon carbide (SiC) by using an excitation laser possessing a photon energy (2.33 eV) much lower than the band gap of . By gradually attenuating the intensity of the excitation laser, the effective depth that the laser could generate Raman signals could eventually be limited to within the ultrashallow region of the SiC wafer. Through three-dimensional finite-difference-timedomain (3D-FDTD) simulations, we found that the depth of the high electric field region could be limited from several micrometers below the surface to the near-surface region of 4H-SiC, merely by attenuating the power of the incident laser. Experimentally, we observed a clear trend in the Raman peak intensity ratio of the signals at 210 and 203 cm −1 in the FTA mode: the intensity ratio of the Si face was always higher than that of the C face regardless of the measurement position on the 4H-SiC wafer. Even through the carrier concentrations in the 4H-SiC wafer were nonuniform, the resulting variability in peak intensity did not influence the trend in the intensity ratio, which could, therefore, be used to identify the surface polarity. This approach might also allow characterization of different polytypes of SiC, for example, 6H-SiC and 3C-SiC, the optical band gaps of which are lower than that of 4H-SiC. Because this optical approach using low-photon-energy laser-based Raman spectroscopy is nondestructive, simple, and rapid and employs excitation light of low photon energy, it should be very applicable for characterizing the surface properties of various other crystalline materials.

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Application of channeling-enhanced electron energy-loss spectroscopy for polarity determination in ZnO nanopillars

Cited by 25 publications

References 25 publications

Polarity-Dependent Growth Rates of Selective Area Grown ZnO Nanorods by Chemical Bath Deposition

Polarity-Dependent Growth Rates of Selective Area Grown ZnO Nanorods by Chemical Bath Deposition

The Role of Polarity in Nonplanar Semiconductor Nanostructures

Using Visible Laser-Based Raman Spectroscopy to Identify the Surface Polarity of Silicon Carbide

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