Electronic transport in p‐type Mg‐doped GaAs nanowires

Cifuentes, Nestor; Limborço, H.; Viana, E. R.; Roa, Daniel Bretas; Abelenda, A.; Silva, M. I. N. da; Moreira, M. V. B.; Oliveira, A. G. de; González, J. C.

doi:10.1002/pssb.201600204

Cited by 11 publications

(19 citation statements)

References 28 publications

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“…For a back-gate nanowire FET, the capacitance ( C ) can be estimated considering a metallic cylinder-plane system from [19]:…”

Section: Resultsmentioning

confidence: 99%

“…Standard photolithography methods were used to define several contact lines, with a lateral separation of 3 to 9 μm on individual nanowires. Following this procedure, ohmic contacts with acceptable low contact resistance are obtained [19]. Fig.…”

Section: Methodsmentioning

confidence: 99%

“…The TEM image at the bottom of Fig. 1 shows the typical morphology of the GaAs nanowire, with an axial segmented structure created by the presence of WZ/ZB polytypism [14,17–19]. Fig.…”

Section: Methodsmentioning

confidence: 99%

“…In general, GaAs nanowires show a polytypic structure along the gowth axis that is characterized by the occurrence of a mixture of WZ and ZB phases [12–14]. This fact creates an unintentional bandgap that critically influences the optical and electrical properties of the nanowires [11–19]. In addition to the intentional doping, the distribution of crystalline phases and defects (like stacking faults and twin planes) along the nanowire length depends on the interplay between various growth parameters, namely temperature, effective V/III ratio during the growth and absolute pressure of the system [20–21].…”

Section: Introductionmentioning

confidence: 99%

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Substrate and Mg doping effects in GaAs nanowires

Kannappan¹,

Sédrine²,

Teixeira³

et al. 2017

Beilstein J. Nanotechnol.

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Mg doping of GaAs nanowires has been established as a viable alternative to Be doping in order to achieve p-type electrical conductivity. Although reports on the optical properties are available, few reports exist about the physical properties of intermediate-to-high Mg doping in GaAs nanowires grown by molecular beam epitaxy (MBE) on GaAs(111)B and Si(111) substrates. In this work, we address this topic and present further understanding on the fundamental aspects. As the Mg doping was increased, structural and optical investigations revealed: i) a lower influence of the polytypic nature of the GaAs nanowires on their electronic structure; ii) a considerable reduction of the density of vertical nanowires, which is almost null for growth on Si(111); iii) the occurrence of a higher WZ phase fraction, in particular for growth on Si(111); iv) an increase of the activation energy to release the less bound carrier in the radiative state from nanowires grown on GaAs(111)B; and v) a higher influence of defects on the activation of nonradiative de-excitation channels in the case of nanowires only grown on Si(111). Back-gate field effect transistors were fabricated with individual nanowires and the p-type electrical conductivity was measured with free hole concentration ranging from 2.7 × 1016 cm−3 to 1.4 × 1017 cm−3. The estimated electrical mobility was in the range ≈0.3–39 cm2 /Vs and the dominant scattering mechanism is ascribed to the WZ/ZB interfaces. Electrical and optical measurements showed a lower influence of the polytypic structure of the nanowires on their electronic structure. The involvement of Mg in one of the radiative transitions observed for growth on the Si(111) substrate is suggested.

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“…For a back-gate nanowire FET, the capacitance ( C ) can be estimated considering a metallic cylinder-plane system from [19]:…”

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…The TEM image at the bottom of Fig. 1 shows the typical morphology of the GaAs nanowire, with an axial segmented structure created by the presence of WZ/ZB polytypism [14,17–19]. Fig.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Substrate and Mg doping effects in GaAs nanowires

Kannappan¹,

Sédrine²,

Teixeira³

et al. 2017

Beilstein J. Nanotechnol.

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show abstract

“…In recent years many studies have been devoted to the study of semiconductor nanowires (NWs). [1][2][3][4] These nanostructures have attracted great interest due to their versatile optical [2][3][4] and electrical properties, [4][5][6] allowing them to be used as a building block for devices [4][5][6][7][8][9] or even as an effective platform for an interface with biological systems. [10][11][12] Thus, understanding the optical properties of these NWs is fundamental for the development of new technologies.…”

Section: Introductionmentioning

confidence: 99%

Photodegradation of Si-doped GaAs nanowire

et al. 2019

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Researching optical effects in nanowires may require a high pump intensity which under ambient conditions can degrade nanowires due to thermal oxidation. In this work we investigated the photodegradation of a single Si-doped GaAs nanowire by laser heating in air. To understand the changes that occurred on the nanowire we carried out Raman spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and photoluminescence spectroscopy in laser damaged regions as well as in non-affected ones. From Raman Stokes and anti-Stokes measurements we estimated the local temperature that the oxidation process of the nanowire (NW) surface starts at as 661 K, resulting in two new Raman modes at 200 cm À1 and 259 cm À1 . Scanning electron microscopy and energy dispersive X-ray spectroscopy measurements showed a significant loss of arsenic in the oxidized regions, but no erosion of the nanowire. Micro-photoluminescence measurements showed the near-band-edge emission of GaAs along the nanowire, as well as a new emission band at 755 nm corresponding to polycrystalline b-Ga 2 O 3 formation. Our results also indicate that neither amorphous As nor crystalline As were deposited on the surface of the nanowire. Combining different experimental techniques, this study showed the formation of polycrystalline b-Ga 2 O 3 by oxidation of the nanowire surface and the limits for performing spectroscopic investigations on individual GaAs NWs under ambient air conditions.

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Deciphering the Role of Defects in the Ambipolar Electrical Transport in Nanocrystalline Sb₂Se₃ Thin Films

González

Limborço

Ribeiro‐Andrade

et al. 2021

Adv Elect Materials

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The role of two defects in the ambipolar character of nanocrystalline selenium poor Sb2Se3 is studied. At low temperature, the electrical transport in Sb2Se3 thin films with nm‐sized crystallites and grains is dominated by the ionization of a shallow acceptor, while at high temperature a deep donor is the leading one. The ionization energy of the deep donor agrees with theoretical reports for selenium vacancies. However, the value of the ionization energy of the shallow acceptor is in contradiction with theoretical reports pointing out to an unreported shallow defect. These findings have been confirmed by two independent experimental techniques, Electron Paramagnetic Resonance, and electrical transport as a function of temperature. The mobility of the free carriers has been found not to be limited by grain potential barriers (GPB), in contrast with polycrystalline thin films. Both findings, new shallow acceptor and zero height GPB, constitute advantages for the design of nanostructured Sb2Se3‐based solar cells and other optoelectronic devices. These results not only provide useful information for the growth of nanocrystalline Sb2Se3 thin films with ambipolar transport properties, but also about the complexity of defect physics in low‐symmetry and Q1D semiconductors.

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Electronic transport in p‐type Mg‐doped GaAs nanowires

Cited by 11 publications

References 28 publications

Substrate and Mg doping effects in GaAs nanowires

Substrate and Mg doping effects in GaAs nanowires

Photodegradation of Si-doped GaAs nanowire

Deciphering the Role of Defects in the Ambipolar Electrical Transport in Nanocrystalline Sb₂Se₃ Thin Films

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Electronic transport in p‐type Mg‐doped GaAs nanowires

Cited by 11 publications

References 28 publications

Substrate and Mg doping effects in GaAs nanowires

Substrate and Mg doping effects in GaAs nanowires

Photodegradation of Si-doped GaAs nanowire

Deciphering the Role of Defects in the Ambipolar Electrical Transport in Nanocrystalline Sb2Se3 Thin Films

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Product

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Deciphering the Role of Defects in the Ambipolar Electrical Transport in Nanocrystalline Sb₂Se₃ Thin Films