Theoretical Prediction of Heterogeneous Integration of Dissimilar Semiconductor with Various Ultra-Thin Oxides and 2D Materials

2021 ◽  
Vol 2 (4) ◽  
pp. 495-503
Author(s):  
Md Nazmul Hasan ◽  
Chenxi Li ◽  
Junyu Lai ◽  
Jung-Hun Seo
Keyword(s):  
Quantum Tunneling ◽  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
Strain Analysis ◽  
Quantum Mechanical ◽  
Heterogeneous Integration ◽  
Oxide Materials ◽  
Quantum Mechanical Tunneling ◽  
Multiphysics Modeling ◽  
Selection Of

In this paper, we build a numerical p-n Si/GaAs heterojunction model using quantum-mechanical tunneling theory with various quantum tunneling interfacial materials including two-dimensional (2D) materials such as hexagonal boron nitride (h-BN) and graphene, and ALD-enabled oxide materials such as HfO2, Al2O3, and SiO2. Their tunneling efficiencies and tunneling currents with different thicknesses were systematically calculated and compared. Multiphysics modeling was used with the aforementioned tunneling interfacial materials to analyze changes in the strain under different temperature conditions. Considering the transport properties and thermal-induced strain analysis, Al2O3, among three oxide materials, and graphene in 2D materials are favorable material choices that offer the highest heterojunction quality. Overall, our results offer a viable route in guiding the selection of quantum tunneling materials for a myriad of possible combinations of new heterostructures that can be obtained with an ultra-thin tunneling intermediate layer.

scholarly journals Chlorosulfuric acid-assisted production of functional 2D materials

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohsen Moazzami Gudarzi ◽  
Maryana Asaad ◽  
Boyang Mao ◽  
Gergo Pinter ◽  
Jianqiang Guo ◽  
...  
Keyword(s):  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
Real Life ◽  
Large Area ◽  
Polar Solvents ◽  
Aspect Ratios ◽  
Two Dimensional Materials ◽  
Liquid Phase Exfoliation

AbstractThe use of two-dimensional materials in bulk functional applications requires the ability to fabricate defect-free 2D sheets with large aspect ratios. Despite huge research efforts, current bulk exfoliation methods require a compromise between the quality of the final flakes and their lateral size, restricting the effectiveness of the product. In this work, we describe an intercalation-assisted exfoliation route, which allows the production of high-quality graphene, hexagonal boron nitride, and molybdenum disulfide 2D sheets with average aspect ratios 30 times larger than that obtained via conventional liquid-phase exfoliation. The combination of chlorosulfuric acid intercalation with in situ pyrene sulfonate functionalisation produces a suspension of thin large-area flakes, which are stable in various polar solvents. The described method is simple and requires no special laboratory conditions. We demonstrate that these suspensions can be used for fabrication of laminates and coatings with electrical properties suitable for a number of real-life applications.

Spin-forbidden heavy-atom tunneling in the ring-closure of triplet cyclopentane-1,3-diyl

2021 ◽  
Author(s):  
Luís P. Viegas ◽  
Cláudio Manaia Nunes ◽  
Rui Fausto
Keyword(s):  
Heavy Atom ◽  
Ring Closure ◽  
Quantum Mechanical ◽  
Quantum Mechanical Tunneling

In 1975, Buchwalter and Closs reported one of the first examples of heavy-atom quantum mechanical tunneling (QMT) by studying the ring closure of triplet cyclopentane-1,3-diyl to singlet bicyclo[2.1.0]pentane in cryogenic...

scholarly journals MoS2/h-BN/Graphene Heterostructure and Plasmonic Effect for Self-Powering Photodetector: A Review

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1672
Author(s):  
Umahwathy Sundararaju ◽  
Muhammad Aniq Shazni Mohammad Haniff ◽  
Pin Jern Ker ◽  
P. Susthitha Menon
Keyword(s):  
Flexible Electronics ◽  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
Optical Power ◽  
Active Regions ◽  
Green Technology ◽  
Plasmonic Effect ◽  
Zero Bias ◽  
Electrical Signals ◽  
Self Powered

A photodetector converts optical signals to detectable electrical signals. Lately, self-powered photodetectors have been widely studied because of their advantages in device miniaturization and low power consumption, which make them preferable in various applications, especially those related to green technology and flexible electronics. Since self-powered photodetectors do not have an external power supply at zero bias, it is important to ensure that the built-in potential in the device produces a sufficiently thick depletion region that efficiently sweeps the carriers across the junction, resulting in detectable electrical signals even at very low-optical power signals. Therefore, two-dimensional (2D) materials are explored as an alternative to silicon-based active regions in the photodetector. In addition, plasmonic effects coupled with self-powered photodetectors will further enhance light absorption and scattering, which contribute to the improvement of the device’s photocurrent generation. Hence, this review focuses on the employment of 2D materials such as graphene and molybdenum disulfide (MoS2) with the insertion of hexagonal boron nitride (h-BN) and plasmonic nanoparticles. All these approaches have shown performance improvement of photodetectors for self-powering applications. A comprehensive analysis encompassing 2D material characterization, theoretical and numerical modelling, device physics, fabrication and characterization of photodetectors with graphene/MoS2 and graphene/h-BN/MoS2 heterostructures with plasmonic effect is presented with potential leads to new research opportunities.

scholarly journals Contact Electrification by Quantum-Mechanical Tunneling

Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Morten Willatzen ◽  
Zhong Lin Wang
Keyword(s):  
Potential Versus ◽  
Coulomb Repulsion ◽  
Quantum Mechanical ◽  
Quantum Mechanical Tunneling ◽  
One Dimensional ◽  
Contact Electrification ◽  
Order Of Magnitude ◽  
Left And Right ◽  
Tunneling Dynamics ◽  
Vacuum Gap

A simple model of charge transfer by loss-less quantum-mechanical tunneling between two solids is proposed. The model is applicable to electron transport and contact electrification between e.g. a metal and a dielectric solid. Based on a one-dimensional effective-mass Hamiltonian, the tunneling transmission coefficient of electrons through a barrier from one solid to another solid is calculated analytically. The transport rate (current) of electrons is found using the Tsu-Esaki equation and accounting for different Fermi functions of the two solids. We show that the tunneling dynamics is very sensitive to the vacuum potential versus the two solids conduction-band edges and the thickness of the vacuum gap. The relevant time constants for tunneling and contact electrification, relevant for triboelectricity, can vary over several orders of magnitude when the vacuum gap changes by one order of magnitude, say, 1 Å to 10 Å. Coulomb repulsion between electrons on the left and right material surfaces is accounted for in the tunneling dynamics.

Quantum mechanical versus quasi-classical tunneling times for smooth potential barriers

2003 ◽  
Vol 81 (3) ◽  
pp. 573-581 ◽  
Author(s):  
M R.A. Shegelski ◽  
E V Kozijn
Keyword(s):  
Quantum Mechanical ◽  
Tunneling Time ◽  
Quantum Mechanical Tunneling ◽  
Potential Barriers ◽  
Smooth Potential ◽  
Tunneling Times

For smooth potential barriers, we compare the quasi-classical tunneling time with an expression that gives a fully quantum mechanical tunneling time. The expression we choose for the quantum mechanical tunneling time is one that has heuristic value. We report results wherein this quantum mechanical tunneling time and the quasi-classical time differ significantly, both quantitatively and qualitatively. To determine the reasons for these differences, we compare the trends in the two times that result from varying the potential. Our findings suggest that, for smooth potential barriers, the quasi-classical tunneling time is unreliable for many cases where it is employed. PACS Nos.: 03.65Xp, 03.65-w

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