Showing papers on "Schottky diode published in 2022"
01 Mar 2022
TL;DR: In this paper , Ru-RuO2 Mott-Schottky heterojunctions have been used as an effective air cathode catalyst for flexible, rechargeable zinc-air batteries.
Abstract: Development of high-efficiency electrocatalysts for pH-universal overall water splitting is a critical step towards a sustainable hydrogen economy. Herein, graphene nanocomposites with Ru-RuO2 Mott-Schottky heterojunctions (Ru-RuO2@NPC) are prepared pyrolytically and exhibit a remarkable electrocatalytic activity at pH = 0–14 towards both oxygen/hydrogen evolution reactions and overall water splitting, as compared to commercial RuO2 and Pt/C. Ru-RuO2@NPC can also be used as an effective air cathode catalyst for flexible, rechargeable zinc-air batteries. Density functional theory calculations show that the formation of Ru-RuO2 heterojunctions moderately enhances the surface charge density of metallic Ru and brings the d states closer to Fermi level, as compared to that of RuO2 alone, leading to improved intrinsic electrocatalytic activity towards these important reactions. These results demonstrate the significance of Mott-Schottky heterojunctions in the development of high-efficiency electrocatalysts for various new energy technologies.
86 citations
TL;DR: In this article, Ru-RuO2-Mott-Schottky heterojunctions are used to increase the surface charge density of metallic Ru and bring the d states closer to Fermi level.
Abstract: Development of high-efficiency electrocatalysts for pH-universal overall water splitting is a critical step towards a sustainable hydrogen economy. Herein, graphene nanocomposites with Ru-RuO2 Mott-Schottky heterojunctions (Ru-RuO2@NPC) are prepared pyrolytically and exhibit a remarkable electrocatalytic activity at pH = 0–14 towards both oxygen/hydrogen evolution reactions and overall water splitting, as compared to commercial RuO2 and Pt/C. Ru-RuO2@NPC can also be used as an effective air cathode catalyst for flexible, rechargeable zinc-air batteries. Density functional theory calculations show that the formation of Ru-RuO2 heterojunctions moderately enhances the surface charge density of metallic Ru and brings the d states closer to Fermi level, as compared to that of RuO2 alone, leading to improved intrinsic electrocatalytic activity towards these important reactions. These results demonstrate the significance of Mott-Schottky heterojunctions in the development of high-efficiency electrocatalysts for various new energy technologies.
86 citations
TL;DR: In this paper , the work functions of laser-induced graphene (LIG) were controlled by adjusting the frequency or speed of the laser, and a series of LIG/GaOx Schottky photodetectors were formed.
Abstract: Laser-induced graphene (LIG) is a simple, environmentally friendly, efficient, and less costly method, as well as can form various shapes on a flexible substrate in situ without the use of masks. More importantly, it can tune the work function of LIG easily by changing laser parameters to control the transportation of carriers. In this work, the work functions of LIG were controlled by adjusting the frequency or speed of the laser, and a series of LIG/GaOx Schottky photodetectors were formed. When the work function of the graphene increases, the Fermi energy is shifted below the crossing point of the Π and Π* bands, and then more electrons or holes can be activated to participate in the conduction process, resulting in low resistance. Meanwhile, a large built-in electric field can be formed when using a high work function LIG, which is more beneficial to separate photo-generated carriers. Enabled by the controllable LIG, LIG/GaOx Schottky photodetectors can be modulated to have high photoresponsivity or self-powered characteristics. Our work provides a high-performance photodetector with excellent mechanical flexibility and long-life stability, promising applications in the flexible optoelectronic fields.
69 citations
TL;DR: In this article , a series of noble-metal-free MoP/In2S3 Schottky heterojunction photocatalysts were synthesized through two-step synthesis.
39 citations
TL;DR: In this paper, the authors highlighted the current literature and explained the synthesis, structure, morphology, modification strategies, and photocatalytic applications of emerging BiPO4-based photocatalyst.
38 citations
TL;DR: In this article , the authors highlighted the current literature and explained the synthesis, structure, morphology, modification strategies, and photocatalytic applications of emerging BiPO 4 -based photocatalyst.
38 citations
TL;DR: In this article , the impact of Fermi level pinning (FLP) on 2D semiconductor devices has been investigated by exploring various origins responsible for the FLP, effects of FLP on two-dimensional device performances, and methods for improving metallic contact to 2D materials.
Abstract: Motivated by the high expectation for efficient electrostatic modulation of charge transport at very low voltages, atomically thin 2D materials with a range of bandgaps are investigated extensively for use in future semiconductor devices. However, researchers face formidable challenges in 2D device processing mainly originated from the out-of-plane van der Waals (vdW) structure of ultrathin 2D materials. As major challenges, untunable Schottky barrier height and the corresponding strong Fermi level pinning (FLP) at metal interfaces are observed unexpectedly with 2D vdW materials, giving rise to unmodulated semiconductor polarity, high contact resistance, and lowered device mobility. Here, FLP observed from recently developed 2D semiconductor devices is addressed differently from those observed from conventional semiconductor devices. It is understood that the observed FLP is attributed to inefficient doping into 2D materials, vdW gap present at the metal interface, and hybridized compounds formed under contacting metals. To provide readers with practical guidelines for the design of 2D devices, the impact of FLP occurring in 2D semiconductor devices is further reviewed by exploring various origins responsible for the FLP, effects of FLP on 2D device performances, and methods for improving metallic contact to 2D materials.
37 citations
TL;DR: In this paper , the authors tune Schottky barriers over Ni/S vacancy-rich Mn0.3Cd0.7S (Ni/MCS-s) composites prepared by self-assembly and photochemical method.
Abstract: Although Schottky barriers at the interface of metal/semiconductor help electron/hole separation in photocatalysis, they also limit the migration of electrons across the interface. Herein, we tune Schottky barriers over Ni/S vacancy-rich Mn0.3Cd0.7S (Ni/MCS-s) composites prepared by self-assembly and photochemical method. The Ni/MCS-s heterostructures exhibits superior hydrogen production activity up to 164.1 mmol/h/g in simulated seawater (3.5 wt% NaCl), which is 68 and 5 times higher than MCS-s and 1 wt% Pt/MCS-s, respectively. The apparent quantum yield reached 60.4% at 420 nm. The excellent photocatalytic performance of Ni/MCS-s results from the coupling of plasmonic Ni and S vacancies, which can effectively lower Schottky barrier and enhance hot electrons across the interface for photocatalytic process. Moreover, the Ni layer effectively prevents the catalyst from being corroded in seawater. This work provides a feasible strategy for designing efficient photocatalysts for solar energy conversion in seawater.
36 citations
TL;DR: In this article , the state-of-the-art β-Ga 2 O 3 Schottky barrier diodes and field-effect transistors are discussed, mainly focusing on development results of the author's group.
Abstract: Abstract Rapid progress in β -gallium oxide ( β -Ga 2 O 3 ) material and device technologies has been made in this decade, and its superior material properties based on the very large bandgap of over 4.5 eV have been attracting much attention. β -Ga 2 O 3 appears particularly promising for power switching device applications because of its extremely large breakdown electric field and availability of large-diameter, high-quality wafers manufactured from melt-grown bulk single crystals. In this review, after introducing material properties of β -Ga 2 O 3 that are important for electronic devices, current status of bulk melt growth, epitaxial thin-film growth, and device processing technologies are introduced. Then, state-of-the-art β -Ga 2 O 3 Schottky barrier diodes and field-effect transistors are discussed, mainly focusing on development results of the author’s group.
33 citations
TL;DR: In this article , the state-of-the-art β-Ga 2 O 3 Schottky barrier diodes and field-effect transistors are discussed, mainly focusing on development results of the author's group.
Abstract: Abstract Rapid progress in β -gallium oxide ( β -Ga 2 O 3 ) material and device technologies has been made in this decade, and its superior material properties based on the very large bandgap of over 4.5 eV have been attracting much attention. β -Ga 2 O 3 appears particularly promising for power switching device applications because of its extremely large breakdown electric field and availability of large-diameter, high-quality wafers manufactured from melt-grown bulk single crystals. In this review, after introducing material properties of β -Ga 2 O 3 that are important for electronic devices, current status of bulk melt growth, epitaxial thin-film growth, and device processing technologies are introduced. Then, state-of-the-art β -Ga 2 O 3 Schottky barrier diodes and field-effect transistors are discussed, mainly focusing on development results of the author’s group.
30 citations
TL;DR: In this paper , a clean van der Waals contact is demonstrated, wherein a metallic 2D material, chlorine-doped SnSe2 (Cl-SnSe2), is used as the high-work-function contact, providing an interface that is free of defects and Fermi-level pinning.
Abstract: Precise control over the polarity of transistors is a key necessity for the construction of complementary metal–oxide–semiconductor circuits. However, the polarity control of 2D transistors remains a challenge because of the lack of a high‐work‐function electrode that completely eliminates Fermi‐level pinning at metal–semiconductor interfaces. Here, a creation of clean van der Waals contacts is demonstrated, wherein a metallic 2D material, chlorine‐doped SnSe2 (Cl–SnSe2), is used as the high‐work‐function contact, providing an interface that is free of defects and Fermi‐level pinning. Such clean contacts made from Cl–SnSe2 can pose nearly ideal Schottky barrier heights, following the Schottky–Mott limit and thus permitting polarity‐controllable transistors. With the integration of Cl–SnSe2 as contacts, WSe2 transistors exhibit pronounced p‐type characteristics, which are distinctly different from those of the devices with evaporated metal contacts, where n‐type transport is observed. Finally, this ability to control the polarity enables the fabrication of functional logic gates and circuits, including inverter, NAND, and NOR.
TL;DR: In this article, a Schottky-functionalized Z-scheme heterojunction photocatalyst Ti3C2/g-C3N4/BiOCl was fabricated by a simple hydrothermal method.
TL;DR: In this paper , a Schottky-functionalized Z-scheme heterojunction photocatalyst Ti3C2/g-C3N4/BiOCl was fabricated by a simple hydrothermal method.
TL;DR: In this article , three metal-organic frameworks (MOFs) are chosen to mimic inert or active supports for Pt nanoparticles (NPs) and the photocatalysis is studied, and the formation of Schottky junction between Pt and the MOFs, leading to electron donation effect of the MOF.
Abstract: Charge transfer between metal sites and supports is crucial for catalysis. Redox-inert supports are usually unfavorable due to their less electronic interaction with metal sites, which, we demonstrate, is not always correct. Herein, three metal-organic frameworks (MOFs) are chosen to mimic inert or active supports for Pt nanoparticles (NPs) and the photocatalysis is studied. Results demonstrate the formation of Schottky junction between Pt and the MOFs, leading to electron donation effect of the MOFs. Under light irradiation, both the MOF electron donation effect and Pt interband excitation dominate the Pt electron density. Compared with the "active" UiO-66 and MIL-125 supports, Pt NPs on the "inert" ZIF-8 exhibit higher electron density due to the higher Schottky barrier, resulting in superior photocatalytic activity. This work optimizes metal catalysts with non-reducible support, and promotes the understanding of the relationship between metal-support interaction and photocatalysis.
TL;DR: In this paper , the issues related with conventional photocatalysis such as fast recombination of photo-generated electron and the high recombination time are discussed, and the most widely used technologies for environmental remediation are discussed.
Abstract: Photocatalysis with nanostructured semiconductors is one of the most widely used technologies for environmental remediation. However, the issues related with conventional photocatalysis such as fast recombination of photo-generated electron and...
TL;DR: In this paper , the authors investigated the electronic and interfacial features of metal/semiconductor MoSH/MoSi2N4 van der Waals (vdW) contact.
Abstract: Following the successful synthesis of single-layer metallic Janus MoSH and semiconducting MoSi2N4, we investigate the electronic and interfacial features of metal/semiconductor MoSH/MoSi2N4 van der Waals (vdW) contact. We find that the metal/semiconductor MoSH/MoSi2N4 contact forms p-type Schottky contact (p-ShC type) with small Schottky barrier (SB), suggesting that Janus MoSH can be considered as an efficient metallic contact to MoSi2N4 semiconductor with high charge injection efficiency. The electronic structure and interfacial features of the MoSH/MoSi2N4 vdW heterostructure are tunable under strain and electric fields, which give rise to the SB change and the conversion from p-ShC to n-ShC type and from ShC to Ohmic contact. These findings could provide a new pathway for the design of optoelectronic applications based on metal/semiconductor MoSH/MoSi2N4 vdW heterostructures.
TL;DR: In this article , an all-van-der-Waals barrier-free hole contact between p-type tellurene semiconductor and layered 1T′-WS2 semimetal is reported, which achieves a zero Schottky barrier height of 3 ± 9 meV and a high field effect mobility of ≈1304 cm2 V−1 s−1.
Abstract: Ultrathin 2D semiconductor devices are considered to have beyond‐silicon potential but are severely troubled by the high Schottky barriers of the metal–semiconductor contacts, especially for p‐type semiconductors. Due to the severe Fermi‐level pinning effect and the lack of conventional semimetals with high work functions, their Schottky hole barriers are hardly removed. Here, an all‐van‐der‐Waals barrier‐free hole contact between p‐type tellurene semiconductor and layered 1T′‐WS2 semimetal is reported, which achieves a zero Schottky barrier height of 3 ± 9 meV and a high field‐effect mobility of ≈1304 cm2 V–1 s–1. The formation of such contacts can be attributed to the higher work function of ≈4.95 eV of the 1T′‐WS2 semimetal, which is in sharp contrast with low work function (4.1–4.7 eV) of conventional semimetals. The study defines an available strategy for eliminating the Schottky barrier of metal–semiconductor contacts, facilitating 2D‐semiconductor‐based electronics and optoelectronics to extend Moore's law.
TL;DR: In this paper , a vertical β-Ga2O3 Schottky barrier diode (SBD) with the advanced termination structure of p-type NiOx and n-type β-GAspO3 heterojunctions and coupled field plate structures to alleviate the crowding electric field was acquired, yielding a state-of-the-art direct current Baliga's power figure of merit of 1.11
Abstract: This work acquires a vertical β-Ga2O3 Schottky barrier diode (SBD) with the advanced termination structure of p-type NiOx and n-type β-Ga2O3 heterojunctions and coupled field plate structures to alleviate the crowding electric field. A Ga2O3 SBD delivers an average breakdown voltage of 1860 V and a specific on-resistance of 3.12 mΩ cm2, yielding a state-of-the-art direct-current Baliga's power figure of merit of 1.11 GW/cm2 at an anode area of 2.83 × 10−5 cm2. In addition, the Ga2O3 SBD with the same fabrication process at a large area of 1.21 × 10−2 cm2 also presents a high forward current of 7.13 A, a breakdown voltage of 1260 V, and a power figure-of-merit of 235 MW/cm2. According to dynamic pulse switching and capacitance-frequency characteristics, an optimized p-NiOx/Ga2O3 interface with a maximum trap density of 4.13 × 1010 eV−1 cm−2 is delivered. Moreover, based on the forward current-voltage measurement at various temperatures, the physics behind a forward conduction mechanism is illustrated. Ga2O3 SBDs with p-NiOx/n-Ga2O3 heterojunction termination, field plate, high power figure of merit, and high quality interface as well as suppressed resistance increase after dynamic pulse switching, verifying their great promise for future high power applications.
TL;DR: In this paper , the inherent physical and photoelectrochemical characters of the obtained Ti3C2 MXene/Zn3In2S6 Schottky junctions were fully characterized.
TL;DR: In this article , a vertical Ga2O3 Schottky barrier diodes (SBDs) with a staircase field plate on a deep trench filled with SiO2 was presented.
Abstract: This study presents vertical Ga2O3 Schottky barrier diodes (SBDs) with a staircase field plate on a deep trench filled with SiO2. It was clarified from device simulation that at high reverse voltage operation, the staircase field plate and the deep trench can effectively alleviate electric field concentration in the Ga2O3 drift layer and the SiO2 layer, respectively. The Ga2O3 SBDs successfully demonstrated superior device characteristics typified by an on-resistance of 7.6 mΩ cm2 and an off-state breakdown voltage of 1.66 kV. These results offer the availability of the trench staircase field plate as an edge termination structure for the development of Ga2O3 SBDs.
TL;DR: In this article , an interfacial contact Ti 3 C 2 MXene/ZnIn 2 S 4 nanosheets Schottky heterostructure for enhancing photocatalytic environment remediation was constructed by simple low temperature hydrothermal method.
TL;DR: In this article , 2D transition metal dichalcogenides (TMDs) have unique physical, chemical, and mechanical properties and thus they are ideal sensing materials for sensor nodes.
Abstract: 2D transition metal dichalcogenides (TMDs), such as MoS2, MoSe2, WS2, WSe2, etc. have unique physical, chemical, and mechanical properties and thus they are ideal sensing materials. 2D TMDs-based sensor have...
TL;DR: In this paper , lead-free all-inorganic perovskites with broad bandgaps and low work functions are adopted to decorate the surfaces of GaSb nanowires.
Abstract: The surface Fermi level pinning effect promotes the formation of metal-independent Ohmic contacts for the high-speed GaSb nanowires (NWs) electronic devices, however, it limits next-generation optoelectronic devices. In this work, lead-free all-inorganic perovskites with broad bandgaps and low work functions are adopted to decorate the surfaces of GaSb NWs, demonstrating the success in the construction of Schottky-contacts by surface engineering. Benefiting from the expected Schottky barrier, the dark current is reduced to 2 pA, the Ilight /Idark ratio is improved to 103 and the response time is reduced by more than 15 times. Furthermore, a Schottky-contacted parallel array GaSb NWs photodetector is also fabricated by the contact printing technology, showing a higher photocurrent and a low dark current of 15 pA, along with the good infrared photodetection ability for a concealed target. All results guide the construction of Schottky-contacts by surface decorations for next-generation high-performance III-V NWs optoelectronics devices.
TL;DR: In this article , single-crystal chemical vapour deposition (CVD) diamond samples with asymmetric Schottky contacts were used for the fabrication of vertical metal-semiconductor-metal detectors for deep ultraviolet (UV-C) radiation.
TL;DR: In this article , the Mott-Schottky catalysts composed of a metal-semiconductor heterojunction with predictable and designable interfacial synergy are reviewed and discussed.
Abstract: The functions of interfacial synergy in heterojunction catalysts are diverse and powerful, providing a route to solve many difficulties in energy conversion and organic synthesis. Among heterojunction-based catalysts, the Mott-Schottky catalysts composed of a metal-semiconductor heterojunction with predictable and designable interfacial synergy are rising stars of next-generation catalysts. We review the concept of Mott-Schottky catalysts and discuss their applications in various realms of catalysis. In particular, the design of a Mott-Schottky catalyst provides a feasible strategy to boost energy conversion and chemical synthesis processes, even allowing realization of novel catalytic functions such as enhanced redox activity, Lewis acid-base pairs, and electron donor-acceptor couples for dealing with the current problems in catalysis for energy conversion and storage. This review focuses on the synthesis, assembly, and characterization of Schottky heterojunctions for photocatalysis, electrocatalysis, and organic synthesis. The proposed design principles, including the importance of constructing stable and clean interfaces, tuning work function differences, and preparing exposable interfacial structures for designing electronic interfaces, will provide a reference for the development of all heterojunction-type catalysts, electrodes, energy conversion/storage devices, and even super absorbers, which are currently topics of interest in fields such as electrocatalysis, fuel cells, CO2 reduction, and wastewater treatment.
TL;DR: In this article , defect levels in Ni/4H-SiC Schottky diode implanted with 200 MeV Ag14+ ions at a fluence of 1×1012 ions/cm2, employing deep level transient spectroscopic technique.
TL;DR: In this paper, defect levels in Ni/4H-SiC Schottky diode implanted with 200 MeV Ag14+ ions at a fluence of 1×1012 ions/cm2, employing deep level transient spectroscopic technique.
TL;DR: In this paper , a two-dimensional interfacial Schottky heterojunction was constructed by depositing ultrathin and flaky Ti 3 C 2 T x (FTC) on ZnO films, which can facilitate the separation of photogenerated electronholes under the piezo-polarization charges induced by piezoelectricity.
TL;DR: In this paper , a Schottky photodiode based on 2D Bi2O2Se is constructed by employing an asymmetric electrodes technology, and the photodetector shows a broadband response from 450 to 1400 nm (Visible-NIR), and the responsivity and detectivity reach 1.2 A W−1 and 7 × 1011 Jones under the irradiation of 500 nm light (6.4 mW cm−2).
Abstract: Two‐dimensional Bi2O2Se is a newly developed 2D semiconductor material with air stability, moderate bandgap (0.8 eV), and high carrier mobility, which shows a bright prospect in optoelectronics. However, the reported photodetectors based on 2D Bi2O2Se suffer from the disadvantage of high dark current on account of the high carrier mobility and conductivity. Here, a Schottky photodiode based on 2D Bi2O2Se is constructed by employing an asymmetric electrodes technology. Due to the Schottky barrier, the dark current of the device is significantly suppressed. And the photodetector avoids the complex and precise preparation process of traditional heterojunction devices. The photodetector shows a broadband response from 450 to 1400 nm (Visible‐NIR), and the responsivity and detectivity reach 1.2 A W−1 and 7 × 1011 Jones under the irradiation of 500 nm light (6.4 mW cm−2), respectively. Moreover, the device achieved On/Off ratios of more than three orders of magnitude and fast response at zero bias (117 ms for rise time and 58.5 ms for fall time). What's more, the responsivity reaches 193 A W−1, and the external quantum efficiency exceeds 47 899% with external bias (−0.5 V). These results indicate the unlimited potential of 2D Bi2O2Se in highly sensitive, broadband, and low‐power optoelectronics devices.