Defects and Optoelectronic Properties in 2D Semiconductors

2020 ◽  
Vol 29 (9) ◽  
pp. 11-14
Author(s):  
Hyun Seok LEE
Keyword(s):  
Room Temperature ◽  
Van Der Waals ◽  
Atomic Layer ◽  
Optoelectronic Properties ◽  
Coulomb Interactions ◽  
Native Defects ◽  
2D Semiconductors ◽  
Low Dimensionality ◽  
Excitonic Emission ◽  
Optoelectronic Applications

Two-dimensional (2D) van der Waals semiconductors have potential for various optoelectronic applications, owing to their unique optical and electrical properties at an atomic layer thickness. A stable excitonic emission from 2D monolayer semiconductors at room temperature, owing to a reduced dielectric screening effect, opens new fields of research on excitonics and valleytronics. Moreover, their low dimensionality without surface dangling bonds allows for unique quantum transport phenomena via artificial van der Waals stacking using a versatile library of 2D materials. In this article, the author introduces the tunable quantum optoelectronic properties of 2D semiconductors by manipulating native defects, van der Waals interfaces, Coulomb interactions, etc. Additionally, the author reviews the electronic and the optoelectronic applications utilizing such unique tunable properties of 2D semiconductors.

Hierarchical computational screening of layered lead-free metal halide perovskites for optoelectronic applications

2021 ◽  
Author(s):  
Qiuqi Li ◽  
Dan Cao ◽  
Xueyin Liu ◽  
Xiangyu Zhou ◽  
Xiaoshuang Chen ◽  
...  
Keyword(s):  
High Stability ◽  
Screening Method ◽  
Optoelectronic Properties ◽  
Metal Halide ◽  
Lead Free ◽  
Computational Screening ◽  
Halide Perovskites ◽  
Optoelectronic Applications ◽  
Free Metal

A hierarchical computational screening method is used to find layered lead-free metal halide perovskites with high stability and outstanding optoelectronic properties.

scholarly journals Mid infrared polarization engineering via sub-wavelength biaxial hyperbolic van der Waals crystals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saurabh Dixit ◽  
Nihar Ranjan Sahoo ◽  
Abhishek Mall ◽  
Anshuman Kumar
Keyword(s):  
Room Temperature ◽  
Extinction Ratio ◽  
Polarization State ◽  
Van Der Waals ◽  
Photonic Devices ◽  
Mid Infrared ◽  
Precise Control ◽  
Electromagnetic Simulations ◽  
Frequency Regime ◽  
Sub Wavelength

AbstractMid-infrared (IR) spectral region is of immense importance for astronomy, medical diagnosis, security and imaging due to the existence of the vibrational modes of many important molecules in this spectral range. Therefore, there is a particular interest in miniaturization and integration of IR optical components. To this end, 2D van der Waals (vdW) crystals have shown great potential owing to their ease of integration with other optoelectronic platforms and room temperature operation. Recently, 2D vdW crystals of $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2 \hbox {O}_5$$ V 2 O 5 have been shown to possess the unique phenomenon of natural in-plane biaxial hyperbolicity in the mid-infrared frequency regime at room temperature. Here, we report a unique application of this in-plane hyperbolicity for designing highly efficient, lithography free and extremely subwavelength mid-IR photonic devices for polarization engineering. In particular, we show the possibility of a significant reduction in the device footprint while maintaining an enormous extinction ratio from $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2$$ V 2 $$\hbox {O}_5$$ O 5 based mid-IR polarizers. Furthermore, we investigate the application of sub-wavelength thin films of these vdW crystals towards engineering the polarization state of incident mid-IR light via precise control of polarization rotation, ellipticity and relative phase. We explain our results using natural in-plane hyperbolic anisotropy of $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2$$ V 2 $$\hbox {O}_5$$ O 5 via both analytical and full-wave electromagnetic simulations. This work provides a lithography free alternative for miniaturized mid-infrared photonic devices using the hyperbolic anisotropy of $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2$$ V 2 $$\hbox {O}_5$$ O 5 .

scholarly journals HfS2 thin films deposited at room temperature by an emerging technique, solution atomic layer deposition

2021 ◽  
Author(s):  
Yuanyuan Cao ◽  
Sha Zhu ◽  
Julien Bachmann
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Room Temperature ◽  
Atomic Layer ◽  
Two Dimensional ◽  
Molecular Precursors ◽  
Layer Deposition

The two-dimensional material and semiconducting dichalcogenide hafnium disulfide is deposited at room temperature by atomic layer deposition from molecular precursors dissolved in hexane.

scholarly journals 2D Semiconductor Nanomaterials and Heterostructures: Controlled Synthesis and Functional Applications

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Hongyan Xu ◽  
Mohammad Karbalaei Akbari ◽  
Serge Zhuiykov
Keyword(s):  
Liquid Metals ◽  
Chemical Vapor ◽  
Atomic Layer ◽  
First Century ◽  
2D Semiconductors ◽  
Layer Deposition ◽  
Semiconductor Nanomaterials ◽  
2D Nanomaterials ◽  
Novel Applications ◽  
Electronic Technologies

AbstractTwo-dimensional (2D) semiconductors beyond graphene represent the thinnest stable known nanomaterials. Rapid growth of their family and applications during the last decade of the twenty-first century have brought unprecedented opportunities to the advanced nano- and opto-electronic technologies. In this article, we review the latest progress in findings on the developed 2D nanomaterials. Advanced synthesis techniques of these 2D nanomaterials and heterostructures were summarized and their novel applications were discussed. The fabrication techniques include the state-of-the-art developments of the vapor-phase-based deposition methods and novel van der Waals (vdW) exfoliation approaches for fabrication both amorphous and crystalline 2D nanomaterials with a particular focus on the chemical vapor deposition (CVD), atomic layer deposition (ALD) of 2D semiconductors and their heterostructures as well as on vdW exfoliation of 2D surface oxide films of liquid metals.

RECENT DEVELOPMENTS ON 3D INTEGRATION OF METALLIC SET ONTO CMOS PROCESS FOR MEMORY APPLICATION

2012 ◽  
Vol 11 (04) ◽  
pp. 1240024 ◽  
Author(s):  
N. JOUVET ◽  
M. A. BOUNOUAR ◽  
S. ECOFFEY ◽  
C. NAUENHEIM ◽  
A. BEAUMONT ◽  
...  
Keyword(s):  
Room Temperature ◽  
Memory Cell ◽  
Atomic Layer ◽  
Cmos Process ◽  
3D Integration ◽  
Simulation Tools ◽  
Layer Deposition ◽  
Recent Developments ◽  
Sram Memory ◽  
Electrical Characterizations

This work presents a nanodamascene process for a CMOS back-end-of-line fabrication of metallic single electron transistor(SET), together with the use of simulation tools for the development of a SET SRAM memory cell. We show room temperature electrical characterizations of SETs fabricated on CMOS with relaxed dimensions, and simulations of a SET SRAM memory cell. Using their physical characteristics achievable through the use of atomic layer deposition, it will be demonstrated that it has the potential to operate at temperature up to 398 K, and that power consumption is less than that of equivalent circuit in advanced CMOS technologies. In order to take advantage of both low power SETs and high CMOS drive efficiency, a hybrid 3D SET CMOS circuit is proposed.

scholarly journals Room Temperature Electroluminescence from Mechanically Formed van der Waals III-VI Homojunctions and Heterojunctions

2014 ◽  
Vol 2 (11) ◽  
pp. 1064-1069 ◽  
Author(s):  
Nilanthy Balakrishnan ◽  
Zakhar R. Kudrynskyi ◽  
Michael W. Fay ◽  
Garry W. Mudd ◽  
Simon A. Svatek ◽  
...  
Keyword(s):  
Room Temperature ◽  
Van Der Waals

scholarly journals All-optical dynamic tuning of local excitonic emission of monolayer MoS2 by integration with Ge2Sb2Te5

Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2351-2359
Author(s):  
Hao Ouyang ◽  
Haitao Chen ◽  
Yuxiang Tang ◽  
Jun Zhang ◽  
Chenxi Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Optical Networks ◽  
Dominant Role ◽  
Laser Pulses ◽  
Coulomb Interactions ◽  
Optical Modulators ◽  
Dynamic Tuning ◽  
All Optical ◽  
Excitonic Emission

AbstractStrong quantum confinement and coulomb interactions induce tightly bound quasiparticles such as excitons and trions in an atomically thin layer of transitional metal dichalcogenides (TMDs), which play a dominant role in determining their intriguing optoelectronic properties. Thus, controlling the excitonic properties is essential for the applications of TMD-based devices. Here, we demonstrate the all-optical tuning of the local excitonic emission from a monolayer MoS2 hybridized with phase-change material Ge2Sb2Te5 (GST) thin film. By applying pulsed laser with different power on the MoS2/GST heterostructure, the peak energies of the excitonic emission of MoS2 can be tuned up to 40 meV, and the exciton/trion intensity ratio can be tuned by at least one order of magnitude. Raman spectra and transient pump-probe measurements show that the tunability originated from the laser-induced phase change of the GST thin film with charge transferring from GST to the monolayer MoS2. The dynamic tuning of the excitonic emission was all done with localized laser pulses and could be scaled readily, which pave a new way of controlling the excitonic emission in TMDs. Our findings could be potentially used as all-optical modulators or switches in future optical networks.

Direct Nanoscale Patterning by Atomic Manipulation

1995 ◽  
Vol 380 ◽  
Author(s):  
Craig T. Salling
Keyword(s):  
Scanning Tunneling Microscope ◽  
Room Temperature ◽  
Atomic Layer ◽  
Sample Surface ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Nanoscale Patterning ◽  
Direct Patterning ◽  
Scale Structures ◽  
Atomic Manipulation

ABSTRACTThe ability to create atomic-scale structures with the scanning tunneling microscope (STM) plays an important role in the development of a future nanoscale technology. I briefly review the various modes of STM-based fabrication and atomic manipulation. I focus on using a UHV-STM to directly pattern the Si(001) surface by atomic manipulation at room temperature. By carefully adjusting the tip morphology and pulse voltage, a single atomic layer can be removed from the sample surface to define features one atom deep. Segments of individual dimer rows can be removed to create structures with atomically straight edges and with lateral features as small as one dimer wide. Trenches ∼3 nm wide and 2–3 atomic layers deep can be created with less stringent control of patterning parameters. Direct patterning provides a straightforward route to the fabrication of nanoscale test structures under UHV conditions of cleanliness.

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