Oxygen adsorption at noble metal/TiO<sub>2</sub>junctions

Hossein‐Babaei, Faramarz; Alaei-Sheini, Navid; Lajvardi, Mehdi Mohamadzade

doi:10.1088/1757-899x/108/1/012030

Cited by 10 publications

(7 citation statements)

References 26 publications

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“…This result is consistent with the reported independence of the height of the junction barrier formed on TiO 2 by various metals . For Au/TiO 2 , however, these numerical values lead to a barrier height approximately around 0.4 eV . A much higher barrier value in our case indicates a complex junction nature.…”

Section: Resultssupporting

confidence: 92%

“…The nonlinearity is expected to stem from the Au/TiO 2 junction, which has been reported earlier by Chakrabartty et al and Karaagac et al However, Figure a shows that S0 (seed layer) exhibits almost symmetric and linear J d – V characteristics, indicating an almost zero junction barrier height. The linear and symmetric behavior observed in the J – V characteristics around V = 0 originates from the trap-populated TiO 2 surface layer adjacent to the interface, as observed by others . It has been shown previously that a high V O concentration can break the interface barrier in M/TiO 2 junctions .…”

Section: Resultssupporting

confidence: 77%

“…The linear and symmetric behavior observed in the J – V characteristics around V = 0 originates from the trap-populated TiO 2 surface layer adjacent to the interface, as observed by others. 43 It has been shown previously that a high V O concentration can break the interface barrier in M/TiO 2 junctions. 44 Our results indicate that the PLD seed layer contains abundant surface trap states (probably V O ) because of a deposition condition of high vacuum (i.e., nonavailability of O 2 ) in the growth chamber.…”

Section: Resultsmentioning

confidence: 92%

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Defect-Assisted Broad-Band Photosensitivity with High Responsivity in Au/Self-Seeded TiO₂ NR/Au-Based Back-to-Back Schottky Junctions

et al. 2019

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TiO 2 nanorods (NRs) have generated much interest for both fundamental understanding of defect formation and technological applications in energy harvesting, optoelectronics, and catalysis. Herein, we have grown TiO 2 NR films on glass substrates using a self-seeded approach and annealed them in H 2 ambient to modify their surface defects. It has been shown that broad-band photosensing properties of Au/self-seeded TiO 2 NR/Au-based two back-to-back Schottky junctions (SJs) for a broad wavelength of light are much superior as compared to those of the pristine and the control samples. Photoresponsivity values for the H 2 -annealed sample are 0.42, 0.71, 0.07, and 0.08 A/W for detecting, respectively, 350, 400, 470, and 570 nm lights. Very low dark current and high photocurrent lead to a gain value as high as 1.85 × 10 4 for 400 nm light. Unprecedentedly modified NR-based SJs show excellent photoresponsivity for detecting as low as 25, 36, 48, and 28 μW/cm 2 power densities of 350, 400, 470, and 570 nm lights, respectively. It is found that Ti 3+ defects play a key role in an efficient photoelectron transfer from TiO 2 to Au. Our work, for the first time, highlights the simplicity and reveals the rationale behind the excellent properties of Au/self-seeded TiO 2 NR film/Au back-to-back SJs.

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Section: Resultssupporting

confidence: 92%

Section: Resultssupporting

confidence: 77%

Section: Resultsmentioning

confidence: 92%

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Defect-Assisted Broad-Band Photosensitivity with High Responsivity in Au/Self-Seeded TiO₂ NR/Au-Based Back-to-Back Schottky Junctions

et al. 2019

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“…Moreover, it has been reported that Schottky type contact is essential on TiO 2 to enable resistive switching [15], making the study of the interface effects of particular interest also for memristor based application. In turn, the properties of Metal/TiO 2 interfaces are intensively studied by several groups over the recent years [16]- [22].…”

Section: Introductionmentioning

confidence: 99%

“…In contrast to the conventional semiconducting materials, this well-defined theory cannot directly be applied on Metal/TiO 2 interfaces. Experimental results demonstrated that this is not a traditional Schottky barrier and rather than the metal work function, it is the metal electronegativity [16], the interface reaction [18], [19], or even the design and/or fabrication details [20]- [22] that could determine the interface properties, although further investigations are still required towards thorough clarification. A common approach on the aforementioned studies is the implementation of distinct metal contacts formed at the top of the TiO 2 films and are benchmarked via the room temperature assessment of their current-voltage characteristic.…”

Section: Introductionmentioning

confidence: 99%

Interface Asymmetry Induced by Symmetric Electrodes on Metal–Al:TiO$_{x}$–Metal Structures

Michalas

Trapatseli

Stathopoulos

et al. 2018

IEEE Trans. Nanotechnology

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Emerging memory technologies have sparked great interest in studying a variety of materials that can be employed in metal-insulator-metal topologies to support resistive switching. While the majority of reports focus on identifying appropriate materials that can be used as active core layers, the selection of electrodes also impacts the performance of such memory devices. Here, both the top and the bottom interfaces of symmetric Metal-Al:TiO x -Metal structures have been investigated by the analysis of their current versus voltage characteristics in the temperature range of 300-350 K. Three different metals were utilized as electrodes, Nb, Au, and Pt, for covering a wide range of work function and electronegativity values. Despite their symmetric structure, the devices were found to exhibit asymmetric performance with respect to the applied bias polarity. Clear signature plots indicating thermionic emission over the interface Schottky barriers have been obtained. The asymmetry between the top and the bottom interfaces was further evaluated by the values of the potential barrier heights and by the barrier lowering factors, both calculated from the experimental data. This study highlights the importance of the interface effects and proves that in addition to film doping, proper (top/bottom) metal selection, and interface engineering should also be exploited for developing thin film metal oxide based devices with tailored electrical characteristics.

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An Absorber Enrichment Study and Implications on the Performance of Lead-Free CsSnI3 Perovskite Solar Cells (PSCs) Using One-Dimensional Solar Cell Capacitance Simulator (1D-SCAPS)

Ahmed,

Ibrahim,

Oladimeji

et al. 2024

Braz J Phys

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Extensive research efforts have been made over the last few years to proffer solution to the high recombination rate and stability issues associated with Sn-based perovskite solar cells. In line with this, we modeled caesium tin iodide (CsSnI3)-based perovskite solar cell (PSC) with titanium (IV) oxide (TiO2) and copper thiocyanate (CuSCN) as the electron and hole transport materials respectively by employing One-Dimensional Solar Cell Capacitance Simulator (1D-SCAPS). For the CsSnI3-based PSC, n-i-p planar configuration was employed and previously published relevant data were used for the simulation. The results obtained for the initially modeled PSC compared well with similar devices in the literature. Based on the established relationship between charge carrier lifetime and power conversion efficiency (PCE) of a solar cell, we varied defect density in the cesium tin iodide (CsSnI3) from 10 13 cm -3 to 10 17 cm -3 and studied its influence on the performance parameters of the modeled CsSnI3-based PSC. We find that the diffusion length and lifetime of charge carriers are significantly increased with decreasing defect density of the CsSnI3 absorber. In this study, we report that it is possible to significantly reduce the dominated Shockley-Read-Hall (SRH) high recombination rate occurring in CsSnI3 perovskite layer even at a low defect density of 10 13 cm -3 by using a combination of SnCl2 and Br − as additive and dopant respectively for CsSnI3 enrichment. This strategy ensured a reduced concentration of Sn 4+ vacancy (VSn) in the CsSnI3 absorber and an improved carrier lifetime beyond 0.05 ns as obtained for the initially modeled CsSnI3 -based PSC by a magnitude of the order of 10 3 while the diffusion length was improved from 1.1µm by a magnitude of the order of 10 2 for the enriched CsSnI3 -based PSC. For the optimized CsSnI3-based PSC, we recorded the following photovoltaic parameters: open-circuit voltage (VOC ) = 1.289 V, short-circuit current density (JSC ) = 32.60 mA.cm -2 , fill factor (FF ) = 83.56% and PCE = 35.12%.

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Oxygen adsorption at noble metal/TiO₂junctions

Cited by 10 publications

References 26 publications

Defect-Assisted Broad-Band Photosensitivity with High Responsivity in Au/Self-Seeded TiO₂ NR/Au-Based Back-to-Back Schottky Junctions

Defect-Assisted Broad-Band Photosensitivity with High Responsivity in Au/Self-Seeded TiO₂ NR/Au-Based Back-to-Back Schottky Junctions

Interface Asymmetry Induced by Symmetric Electrodes on Metal–Al:TiO$_{x}$–Metal Structures

An Absorber Enrichment Study and Implications on the Performance of Lead-Free CsSnI3 Perovskite Solar Cells (PSCs) Using One-Dimensional Solar Cell Capacitance Simulator (1D-SCAPS)

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Oxygen adsorption at noble metal/TiO2junctions

Cited by 10 publications

References 26 publications

Defect-Assisted Broad-Band Photosensitivity with High Responsivity in Au/Self-Seeded TiO2 NR/Au-Based Back-to-Back Schottky Junctions

Defect-Assisted Broad-Band Photosensitivity with High Responsivity in Au/Self-Seeded TiO2 NR/Au-Based Back-to-Back Schottky Junctions

Interface Asymmetry Induced by Symmetric Electrodes on Metal–Al:TiO$_{x}$–Metal Structures

An Absorber Enrichment Study and Implications on the Performance of Lead-Free CsSnI3 Perovskite Solar Cells (PSCs) Using One-Dimensional Solar Cell Capacitance Simulator (1D-SCAPS)

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Oxygen adsorption at noble metal/TiO₂junctions

Defect-Assisted Broad-Band Photosensitivity with High Responsivity in Au/Self-Seeded TiO₂ NR/Au-Based Back-to-Back Schottky Junctions

Defect-Assisted Broad-Band Photosensitivity with High Responsivity in Au/Self-Seeded TiO₂ NR/Au-Based Back-to-Back Schottky Junctions