| 1. |
- de Melo, Claudia, et al.
(författare)
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Semi-Transparent p‑Cu2O/n-ZnO Nanoscale-Film Heterojunctions for Photodetection and Photovoltaic Applications
- 2019
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 2:7, s. 4358-4366
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Tidskriftsartikel (refereegranskat)abstract
- Transparent nanoscale-film heterojunctions based on Cu2O and ZnO were fabricated by atomic layer deposition and reactive magnetron sputtering. The constitutive layers exhibit high crystalline quality and a local epitaxial relation between Cu2O and ZnO was achieved with [110] Cu2O || [001] ZnO and [001] Cu2O || [010] ZnO as evidenced by high resolution transmission electron microscopy and. Cu2O films show very low resistivity and high mobility values of 9–150 Ω cm and 19 cm2/V s, respectively. The Cu2O/ZnO heterojunctions exhibit a nonlinear rectifying behavior characteristic of a p–n junction, self-powered photoresponse under 1 Sun illumination and an average transmittance of 73% in the visible region of the electromagnetic spectrum. These results are promising for all-oxide transparent electronics, photodetection and photovoltaic applications.
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| 2. |
- de Melo, Claudia, et al.
(författare)
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Tunable Localized Surface Plasmon Resonance and Broadband Visible Photoresponse of Cu Nanoparticles/ZnO Surfaces
- 2018
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 10:47, s. 40958-40965
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Tidskriftsartikel (refereegranskat)abstract
- Plasmonic Cu nanoparticles (NP) were successfully deposited on ZnO substrates by atomic layer deposition (ALD) owing to the Volmer–Weber island growth mode. An evolution from Cu NP to continuous Cu films was observed with an increasing number of ALD cycles. Real and imaginary parts of the NP dielectric functions, determined by spectroscopic ellipsometry using an effective medium approach, evidence a localized surface plasmon resonance that can be tuned between the visible and near-infrared ranges by controlling the interparticle spacing and size of the NP. The resulting Cu NP/ZnO device shows an enhanced photoresponse under white light illumination with good responsivity values, fast response times, and stability under dark/light cycles. The significant photocurrent detected for this device is related to the hot-electron generation at the NP surface and injection into the conduction band of ZnO. The possibility of tuning the plasmon resonance together with the photoresponsivity of the device is promising in many applications related to photodetection, photonics, and photovoltaics.
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| 3. |
- Horwat, David, et al.
(författare)
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On the deactivation of the dopant and electronic structure in reactively sputtered transparent Al-doped ZnO thin films
- 2010
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Ingår i: Journal of Physics D. - : IOP Publishing. - 0022-3727 .- 1361-6463. ; 43:13, s. 132003-
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Tidskriftsartikel (refereegranskat)abstract
- We report on the possible origin of electrical heterogeneities in 4 at% Al-doped ZnO (AZO) reactively sputtered films. It is found through the Zn L-3 and Al K edge x-ray absorption near-edge structure that a fraction of the Al dopant is deactivated by its positioning in octahedral conformation with oxygen. This fraction as well as the conductivity, optical bandgap and c-axis parameter of ZnO wurtzite are all found to depend on the sample position during deposition. The present results suggest the formation of a metastable Al2O3 (ZnO) m homologous phase that degrades the electrical conductivity.
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