Monolayer graphene/SiC Schottky barrier diodes with improved barrier height uniformity as a sensing platform for the detection of heavy metals

A vertical diode structure comprising homogeneous monolayer epitaxial graphene on silicon carbide is fabricated by thermal decomposition of a Si-face 4H-SiC wafer in argon atmosphere. Current–voltage characteristics of the graphene/SiC Schottky junction were analyzed by applying the thermionic-emission theory. Extracted values of the Schottky barrier height and the ideality factor are found to be 0.4879 ± 0.013 eV and 1.01803 ± 0.0049, respectively. Deviations of these parameters from average values are smaller than those of previously observed literature data, thereby implying uniformity of the Schottky barrier height over the whole diode area, a stable rectifying behaviour and a good quality of ohmic palladium–graphene contacts. Keeping in mind the strong sensitivity of graphene to analytes we propose the possibility to use the graphene/SiC Schottky diode as a sensing platform for the recognition of toxic heavy metals. Using density functional theory (DFT) calculations we gain insight into the nature of the interaction of cadmium, mercury and lead with graphene as well as estimate the work function and the Schottky barrier height of the graphene/SiC structure before and after applying heavy metals to the sensing material. A shift of the I–V characteristics of the graphene/SiC-based sensor has been proposed as an indicator of presence of the heavy metals. Since the calculations suggested the strongest charge transfer between Pb and graphene, the proposed sensing platform was characterized by good selectivity towards lead atoms and slight interferences from cadmium and mercury. The dependence of the sensitivity parameters on the concentration of Cd, Hg and Pb is studied and discussed.

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Tuning the Schottky barrier height in a multiferroic In2Se3/Fe3GeTe2 van der Waals heterojunction

Nanoscale ◽

10.1039/d1nr06906c ◽

2021 ◽

Author(s):

Maria Javaid ◽

Patrick David Taylor ◽

Sherif Abdulkader Tawfik ◽

Michelle Jeanette Sapountzis Spencer

Keyword(s):

Density Functional Theory ◽

Electronic Properties ◽

Schottky Barrier ◽

Barrier Height ◽

Density Functional ◽

Schottky Barrier Height ◽

Van Der Waals ◽

Ferroelectric Material ◽

Functional Theory ◽

Significant Interest

The ferroelectric material In2Se3 is currently of significant interest due to its built-in polarisation characteristics that can significantly modulate its electronic properties. Here we employ density functional theory to determine...

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Accurate evaluation of Cr/n-Si Schottky barrier height using thermionic emission theory and external resistors

Infrared Sensors, Devices, and Applications XI ◽

10.1117/12.2594066 ◽

2021 ◽

Author(s):

Zih-Chun Su ◽

Ching-Fuh Lin

Keyword(s):

Schottky Barrier ◽

Barrier Height ◽

Schottky Barrier Height ◽

Thermionic Emission ◽

Accurate Evaluation

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Gaussian distribution of Schottky barrier heights on SnO2 nanowires

MRS Proceedings ◽

10.1557/opl.2011.1536 ◽

2011 ◽

Vol 1406 ◽

Cited By ~ 1

Author(s):

Cleber A. Amorim ◽

Olivia M. Berengue ◽

Luana Araújo ◽

Edson R. Leite ◽

Adenilson J. Chiquito

Keyword(s):

Schottky Barrier ◽

Barrier Height ◽

Ideality Factor ◽

Schottky Barrier Height ◽

Series Resistance ◽

Small Deviation ◽

Thermionic Emission ◽

Barrier Heights ◽

Sno2 Nanowires ◽

Different Temperatures

ABSTRACTIn this work, we studied metal/SnO2 junctions using transport properties. Parameters such as barrier height, ideality factor and series resistance were estimated at different temperatures. Schottky barrier height showed a small deviation of the theoretical value mainly because the barrier was considered fixed as described by ideal thermionic emission-diffusion model. These deviations have been explained by assuming the presence of barrier height inhomogeneities. Such assumption can also explain the high ideality factor as well as the Schottky barrier height and ideality factor dependence on temperature.

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The External Electric Field-Induced Tunability of the Schottky Barrier Height in Graphene/AlN Interface: A Study by First-Principles

Nanomaterials ◽

10.3390/nano10091794 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1794

Author(s):

Xuefei Liu ◽

Zhaocai Zhang ◽

Bing Lv ◽

Zhao Ding ◽

Zijiang Luo

Keyword(s):

Electric Field ◽

Schottky Barrier ◽

External Electric Field ◽

Barrier Height ◽

Density Functional ◽

Schottky Barrier Height ◽

Schottky Contact ◽

Valence Band Maximum ◽

Charge Analysis ◽

P Type

Graphene-based van der Waals (vdW) heterojunction plays an important role in next-generation optoelectronics, nanoelectronics, and spintronics devices. The tunability of the Schottky barrier height (SBH) is beneficial for improving device performance, especially for the contact resistance. Herein, we investigated the electronic structure and interfacial characteristics of the graphene/AlN interface based on density functional theory. The results show that the intrinsic electronic properties of graphene changed slightly after contact. In contrast, the valence band maximum of AlN changed significantly due to the hybridization of Cp and Np orbital electrons. The Bader charge analysis showed that the electrons would transfer from AlN to graphene, implying that graphene would induce acceptor states. Additionally, the Schottky contact nature can be effectively tuned by the external electric field, and it will be tuned from the p-type into n-type once the electric field is larger than about 0.5 V/Å. Furthermore, the optical absorption of graphene/AlN is enhanced after contact. Our findings imply that the SBH is controllable, which is highly desirable in nano-electronic devices.

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Tuning the Schottky barrier height of the Pd–MoS2 contact by different strains

Physical Chemistry Chemical Physics ◽

10.1039/c5cp04037j ◽

2015 ◽

Vol 17 (40) ◽

pp. 27088-27093 ◽

Cited By ~ 31

Author(s):

Biao Liu ◽

Li-Juan Wu ◽

Yu-Qing Zhao ◽

Ling-Zhi Wang ◽

Meng-Qiu Cai

Keyword(s):

Electronic Properties ◽

Schottky Barrier ◽

Barrier Height ◽

Density Functional Calculations ◽

Density Functional ◽

Schottky Barrier Height ◽

Different Strains

The structures and electronic properties of the Pd–MoS2 contact are investigated using density functional calculations under different strains.

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THE EFFECT OF NANO AND MICRO POROSITY ON THE SCHOTTKY BARRIER HEIGHT AND IDEALITY FACTOR IN THE I–V CHARACTERISTICS OF PtSi/p-Si IR DETECTOR

Modern Physics Letters B ◽

10.1142/s0217984909017984 ◽

2009 ◽

Vol 23 (05) ◽

pp. 765-771

Author(s):

H. ESHGHI ◽

M. MOHAMMADI

Keyword(s):

Schottky Barrier ◽

Barrier Height ◽

Ideality Factor ◽

Schottky Barrier Height ◽

Thermionic Emission ◽

Ir Detector ◽

Current Voltage ◽

Two Samples ◽

P Type ◽

Silicon Interface

In this paper, the effect of porosity on reverse bias current–voltage characteristics of PtSi/por - Si (p-type) IR detector as a function of temperature is investigated. Our experimental data for two samples with different porosities (50% and 10%) at 300 K and 77 K are reported by Raissi et al.1 These data indicates a breakdown-like behavior. Our analytical model is based on hole thermionic emission with large ideality factor (n ≈ 200). Our calculations show that at each temperature, the Schottky barrier height, as well as the ideality factor, in sample with 10% porosity is bigger than that of 50%. These variations could be due to band gap variations of Si size effect using quantum dot model, and the presence of the relatively high (~1015 cm-2 eV-1) density of states at the silicide/por-silicon interface, respectively.

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Theoretical investigation of Pt monosilicide and several germanides: electronic structure, surface energetics, and work functions

MRS Proceedings ◽

10.1557/proc-980-0980-ii05-43 ◽

2006 ◽

Vol 980 ◽

Author(s):

Manish K. Niranjan ◽

Leonard Kleinman ◽

Alexander A. Demkov

Keyword(s):

Electronic Structure ◽

Schottky Barrier ◽

Barrier Height ◽

Density Functional ◽

Schottky Barrier Height ◽

Cmos Technology ◽

Growth Conditions ◽

Structure Surface ◽

Work Functions ◽

P Type

AbstractWe present a theoretical study of the electronic structure, surface energies and work functions of orthorhombic Pt monosilicide and germanides of Pt, Ni, Y and Hf within the framework of density functional theory (DFT). Our calculated bulk structures are within 1-2% of reported experimental values. Calculated work functsions for the (001) surfaces of PtSi, NiGe and PtGe are 5.12, 4.57 and 4.83 eV, respectively, suggesting that these metals and their alloys can be used as self-aligned contacts to p-type silicon and germanium. Work functions for Y and Hf germanides range from 2.4 to 4.3 eV making them a possible n-type contact material. In addition, we also report an ab-initio calculation of the Schottky-barrier height at the Si(001)/PtSi(001) interface. The p-type Schottky barrier height of 0.28 eV is found in good agreement with predictions of a simple metal induced gap states (MIGS) theory and available experiment. This low barrier suggests PtSi as a low contact resistance junction metal for silicon CMOS technology. We identify the growth conditions necessary to stabilize this orientation.

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Anisotropic effect of piezoelectric polarization on Schottky barrier height in elastically deformed bulk GaN crystal

Applied Physics Letters ◽

10.1063/1.3665250 ◽

2011 ◽

Vol 99 (22) ◽

pp. 222106 ◽

Cited By ~ 6

Author(s):

Roman Nowak

Keyword(s):

Schottky Barrier ◽

Barrier Height ◽

Schottky Barrier Height ◽

Piezoelectric Polarization ◽

Anisotropic Effect ◽

Bulk Gan ◽

Gan Crystal

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A Study about Schottky Barrier Height and Ideality Factor in Thin Film Transistors with Metal/Zinc Oxide Nanoparticles Structures Aiming Flexible Electronics Application

Nanomaterials ◽

10.3390/nano11051188 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1188

Author(s):

Ivan Rodrigo Kaufmann ◽

Onur Zerey ◽

Thorsten Meyers ◽

Julia Reker ◽

Fábio Vidor ◽

...

Keyword(s):

Thin Film ◽

Zinc Oxide ◽

Schottky Barrier ◽

Barrier Height ◽

Flexible Electronics ◽

Thin Film Transistors ◽

Zinc Oxide Nanoparticles ◽

Schottky Barrier Height ◽

Oxide Nanoparticles ◽

Semiconductor Interfaces

Zinc oxide nanoparticles (ZnO NP) used for the channel region in inverted coplanar setup in Thin Film Transistors (TFT) were the focus of this study. The regions between the source electrode and the ZnO NP and the drain electrode were under investigation as they produce a Schottky barrier in metal-semiconductor interfaces. A more general Thermionic emission theory must be evaluated: one that considers both metal/semiconductor interfaces (MSM structures). Aluminum, gold, and nickel were used as metallization layers for source and drain electrodes. An organic-inorganic nanocomposite was used as a gate dielectric. The TFTs transfer and output characteristics curves were extracted, and a numerical computational program was used for fitting the data; hence information about Schottky Barrier Height (SBH) and ideality factors for each TFT could be estimated. The nickel metallization appears with the lowest SBH among the metals investigated. For this metal and for higher drain-to-source voltages, the SBH tended to converge to some value around 0.3 eV. The developed fitting method showed good fitting accuracy even when the metallization produced different SBH in each metal-semiconductor interface, as was the case for gold metallization. The Schottky effect is also present and was studied when the drain-to-source voltages and/or the gate voltage were increased.

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