Optical and Electronic Characteristics of Semiconductor Materials and Devices

A special issue of Symmetry (ISSN 2073-8994). This special issue belongs to the section "Physics".

Deadline for manuscript submissions: closed (31 August 2021) | Viewed by 13649

Special Issue Editor


E-Mail Website
Guest Editor
Department of Electronics Engineering, National Changhua University of Education, Changhua 50007, Taiwan
Interests: two dimensional materials; semiconductor devices and materials; crystal growth and characterization
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Symmetry presents harmonic beauty in many ways, in fields such as the arts, music, and science. The unique properties of semiconductor materials vividly manifest the beauty of symmetry in nature. 1D, 2D, or 3D semiconductor materials are built by atoms arranged in a highly symmetric crystal lattice that extends in one, two, or three directions, respectively. Some 1D and 2D materials with reduced in-plane symmetry exhibit strong in-plane anisotropy in their optical and electronic properties that allow for the realization of new electronic and photonic devices. Symmetry and asymmetry optical cavities are essential for photonic devices. Optoelectronic characteristics can be designed by arranging optical nanostructures or by breaking symmetry. The newly emerging field of topological quantum material, which includes topological insulators and semimetals, is another intriguing example of natural symmetry. These devices’ exotic electronic properties hold great promise for future quantum devises.

This Special Issue is open to original research articles, as well as review articles, which are related to the development and optoelectronic characterization of semiconductor materials and devices. Any applications and/or theoretical works are welcome.

Prof. Der-Yuh Lin
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Symmetry is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • symmetry and asymmetry systems and materials
  • 1D, 2D and 3D semiconductor materials and devices
  • optical and electronic characteristics
  • lasers and optical cavity
  • Micro- and nanostructures
  • photonic crystals
  • topological quantum materials

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

11 pages, 2775 KiB  
Article
Absorption of Light in Finite Semiconductor Nanowire Arrays and the Effect of Missing Nanowires
by Nicklas Anttu
Symmetry 2021, 13(9), 1654; https://doi.org/10.3390/sym13091654 - 08 Sep 2021
Cited by 3 | Viewed by 1774
Abstract
When modelling the absorption in semiconductor nanowire (NW) arrays for solar cell and photodetector applications, the array is typically assumed to be infinitely periodic such that a single unit cell suffices for the simulations. However, any actual array is of a finite extent [...] Read more.
When modelling the absorption in semiconductor nanowire (NW) arrays for solar cell and photodetector applications, the array is typically assumed to be infinitely periodic such that a single unit cell suffices for the simulations. However, any actual array is of a finite extent and might also show varying types of localized defects such as missing or electrically non-contacted individual NWs. Here, we study InP NWs of 2000 nm in length and 180 nm in diameter, placed in a square array of 400 nm in period, giving a rather optimized absorption of sunlight. We show that the absorption in the center NW of a finite N × N array converges already at N = 5 close to the value found for the corresponding infinite array. Furthermore, we show that a missing NW causes an enhanced absorption in neighboring nanowires, which compensates for 77% of the absorption loss due to the missing NW. In other words, an electrically non-contacted NW, which absorbs light but cannot contribute to the external short-circuit current, is a four times worse defect than a missing NW. Full article
Show Figures

Figure 1

18 pages, 1387 KiB  
Article
Symmetry Reduction in FEM Optics Modeling of Single and Periodic Nanostructures
by Henrik Mäntynen, Harri Lipsanen and Nicklas Anttu
Symmetry 2021, 13(5), 752; https://doi.org/10.3390/sym13050752 - 26 Apr 2021
Cited by 3 | Viewed by 2084
Abstract
Numerical optics modeling is an invaluable tool in the design of nanostructures for nanophotonics applications where diffraction effects often lead to complex dependency between the nanostructure geometry and its optical properties and response. In order to analyze, design, and optimize such nanostructures, computationally [...] Read more.
Numerical optics modeling is an invaluable tool in the design of nanostructures for nanophotonics applications where diffraction effects often lead to complex dependency between the nanostructure geometry and its optical properties and response. In order to analyze, design, and optimize such nanostructures, computationally efficient numerical optics modeling methods are required. One way to improve the numerical performance is to exploit symmetries found in many optics problems. By identifying equivalencies and restrictions arising from symmetry, it can be possible to simplify the problem at hand, which is the essence of symmetry reduction. However, applying symmetry reduction in optics modeling problems is not trivial. To the best of our knowledge, symmetry reduction has so-far been applied in finite element method (FEM) optics models only in those specific cases where an incident plane wave shares symmetries with the nanostructure geometry. In this work, we show how to extend the symmetry reduction of FEM optics models to the case of nonsymmetric plane-wave incidence, demonstrate such reduction with numerical examples of incident plane wave absorption in a single nanowire and a periodic nanowire array, and discuss the achieved gains in computational efficiency. Full article
Show Figures

Figure 1

10 pages, 4355 KiB  
Article
Active Suppression of Piezoelectric Ringing in Pockels Cells for Laser Cavity Application
by Giedrius Sinkevicius, Algirdas Baskys and Gintaras Tamošauskas
Symmetry 2021, 13(4), 677; https://doi.org/10.3390/sym13040677 - 14 Apr 2021
Cited by 3 | Viewed by 2333
Abstract
Pockels cells used as electro-optical modulators in high-power high-repetition lasers suffer from piezoelectric ringing phenomenon due to piezoelectric properties of the crystals. A new method for active suppression of the piezoelectric ringing in Pockels cells is proposed in this work. It is based [...] Read more.
Pockels cells used as electro-optical modulators in high-power high-repetition lasers suffer from piezoelectric ringing phenomenon due to piezoelectric properties of the crystals. A new method for active suppression of the piezoelectric ringing in Pockels cells is proposed in this work. It is based on symmetric control of Pockels cell using burst of short positive and negative voltage pulses with the same amplitude instead of a single long pulse for light polarization modulation. Rising and falling edges of pulses of the burst induce symmetrical acoustic waves of the opposite phase and cancel the piezoelectric ringing of the crystal. A new high voltage driver capable of generating positive and negative pulses of tens of nanoseconds of 3 kV magnitude was developed for this purpose. The amplitude of laser beam intensity pulsations caused by the piezoelectric ringing can be reduced up to five times when active suppression method is used for the deuterated potassium dihydrogen phosphate (DKDP) Pockels cell. Such crystals like DKDP, LiNbO3, and LiTaO3 may benefit from the proposed method and find new use in lasers of high repetition rate where piezoelectric ringing is a major limiting factor. Full article
Show Figures

Figure 1

16 pages, 4910 KiB  
Article
A New Macro-Model of Gas Flow and Parameter Extraction for a CMOS-MEMS Vacuum Sensor
by Shu-Jung Chen and Yung-Chuan Wu
Symmetry 2020, 12(10), 1604; https://doi.org/10.3390/sym12101604 - 26 Sep 2020
Cited by 5 | Viewed by 2233
Abstract
When using a MEMS sensor to measure the vacuum of a medium, the transition flow between the viscous flow and molar flow is usually used to describe the gas convection due to the physical principle, which is difficult to study through analysis and [...] Read more.
When using a MEMS sensor to measure the vacuum of a medium, the transition flow between the viscous flow and molar flow is usually used to describe the gas convection due to the physical principle, which is difficult to study through analysis and simulation. In this study, the description of gas flow under different pressures in a CMOS-MEMS vacuum sensors has been incorporated into a new behavioral ANSYS model. The proposed model was built and the characteristic parameters in the model were obtained based on a CMOS-MEMS thermopile patterned with circular symmetry and an embedded heater as a heat source. It contains a characteristic length to describe the effective distance of heat dissipation to the silicon substrate, and the corresponding transition pressure to describe the symmetrical phenomenon of gas heat conduction. The macro-model is based on the description of the physical characteristics of heat transfer and the characteristic parameters of the CMOS-MEMS vacuum sensor. The characteristic length of 49 μm and the corresponding transition pressure of 2396 mTorr for the thermoelectric-type vacuum sensor were extracted and verified successfully. The results show that the average error for the prediction of vacuum sensing by the macro-model we proposed is about 1.11%. This approach provides more applications for vacuum analysis. It can reduce the complexity of simulation and analysis and provide better simulation effects, including gas conduction mechanisms. Full article
Show Figures

Graphical abstract

10 pages, 1890 KiB  
Article
Ferroelectric and Electrical Properties Optimization of Mg-doped BiFeO3 Flexible Multiferroic Films
by Der-Yuh Lin, Hone-Zern Chen, Ming-Cheng Kao and Pei-Li Zhang
Symmetry 2020, 12(7), 1173; https://doi.org/10.3390/sym12071173 - 15 Jul 2020
Cited by 6 | Viewed by 2471
Abstract
Bi1-xMgxFeO3 (BMFO, x = 0, 0.02, 0.04, 0.06 and 0.08) multiferroic films were directly synthesized on flexible stainless steel (FSS), save the bottom electrode process, by means of sol–gel spin-coating technology. The effects of different bending conditions on [...] Read more.
Bi1-xMgxFeO3 (BMFO, x = 0, 0.02, 0.04, 0.06 and 0.08) multiferroic films were directly synthesized on flexible stainless steel (FSS), save the bottom electrode process, by means of sol–gel spin-coating technology. The effects of different bending conditions on ferroelectric, dielectric and leakage-current properties of BMFO films were investigated. The leakage-current densities of BiFeO3 (BFO, x = 0) and BMFO (x = 0.06) films were 5.86 × 10−4 and 3.73 × 10−7 A/cm2, which shows that the BMFO (x = 0.06) has more than three orders of magnitude lower than that of BFO film. The residual polarization (2 Pr) can be enhanced from 120 to 140 μC/cm2. The proper doping of Mg in BiFeO3 film could provide an effective method for reducing the leakage-current values as well as boosting the ferroelectric properties. In this study, the leakage-current mechanism of low electric field and high electric field of BMFO film is analyzed and established. In addition, the flexible BMFO film maintains practical ferroelectric and leakage-current properties at retention time of 106 s under different symmetry bending conditions. These results indicate that the BFMO film will be very practical in opto-electronic and storage device applications. Full article
Show Figures

Figure 1

10 pages, 3399 KiB  
Article
Nanorod Arrays Enhanced UV Light Response of Mg-Doped ZnO Films
by Der-Yuh Lin, Hone-Zern Chen, Ming-Cheng Kao, San-Lin Young and Wen-Yi Sung
Symmetry 2020, 12(6), 1005; https://doi.org/10.3390/sym12061005 - 12 Jun 2020
Cited by 3 | Viewed by 2015
Abstract
Zn1−xMgxO (x = 0, 0.03, 0.05, and 0.07) nanocrystalline films were grown on silicon substrates using the sol–gel method. Furthermore, Zn1−xMgxO vertically aligned hexagonal symmetrical nanorods with six reflection symmetries were fabricated on pure ZnO-seeded [...] Read more.
Zn1−xMgxO (x = 0, 0.03, 0.05, and 0.07) nanocrystalline films were grown on silicon substrates using the sol–gel method. Furthermore, Zn1−xMgxO vertically aligned hexagonal symmetrical nanorods with six reflection symmetries were fabricated on pure ZnO-seeded layer n-type silicon substrates via a low-temperature hydrothermal method to enhance the ultraviolet (UV) light response. The crystal microstructures and surface morphologies of nanocrystalline films and nanorod arrays were determined by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Transmission spectra showed that the increasing Mg content will increase the band gap energy from 3.28 to 3.46 eV. However, the current–voltage curves in the dark and under UV illumination showed that the UV response did not improve by the incorporation of magnesium. We changed the flat surface of films into symmetrical nanorod arrays and demonstrated they can significantly enhance the normalized photo-to-dark-current ratio up to ten times. Full article
Show Figures

Figure 1

Back to TopTop