Bilayer phosphorene attracted considerable interest, giving a potential application in nanoelectronics owing to its natural bandgap and high carrier mobility. However, very little is known regarding the possible usefulness in spintronics as a quantum spin Hall (QSH) state of material characterized by a bulk energy gap and gapless spin-filtered edge states. Here, we report a strain-induced topol...

Tuning the electronic band structures such as band-edge position and bandgap of organic semiconductors is crucial to maximize the performance of organic photovoltaic devices. We present a simple yet effective electron irradiation approach to tune the band structure of [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) that is the most widely used organic acceptor material. We have found that th...

We report a robust method for engineering the optoelectronic properties of many-layer MoS2 using low-energy oxygen plasma treatment. Gas phase treatment of MoS2 with oxygen radicals generated in an upstream N2 -O2 plasma is shown to enhance the photoluminescence (PL) of many-layer, mechanically exfoliated MoS2 flakes by up to 20 times, without reducing the layer thickness of the material. A blu...

Securing a semiconducting bandgap is essential for applying graphene layers in switching devices. Theoretical studies have suggested a created bulk bandgap in a graphene layer by introducing an asymmetry between the A and B sub-lattice sites. A recent transport measurement demonstrated the presence of a bandgap in a graphene layer where the asymmetry was introduced by placing a graphene layer o...

Silicon is the most important semiconductor material for electronics industry. However, its indirect bandgap makes it hardly emit light, so its applications in optoelectromcs are limited. Many efforts had been devoted to converting silicon to light-emitting materials, including porous silicon-based devices, nanociystalline Si, and so on. In this work, we report electroluminescence on silicon wi...

Mahdi Pourfath, Hans Kosina, and Siegfried Selberherr Institute for Microelectronics, TU Wien, Gußhausstraße 27–29/E360, A-1040 Wien, Austria Email: {pourfath|kosina|selberherr}@iue.tuwien.ac.at Graphite-related materials such as carbon nanotubes (CNTs) and graphene have been extensively studied in recent years due to their exceptional electronic, opto-electronic, and mechanical properties. How...

Visible light photocatalysts based on doped crystalline forms of titanium dioxide (TiO2) have attracted significant scientific attention in recent decades. Amorphous TiO2, despite many merits over crystalline phases, has not been studied as thoroughly. In this paper, an in-depth analysis of the electronic properties of doped amorphous TiO2 is performed using density functional theory with Hubba...

A novel donor-acceptor type conjugated polymer based on a building block of 4,8-di(thien-2-yl)-6-octyl-2-octyl-5H-pyrrolo[3,4-f]benzotriazole-5,7(6H)-dione (TZBI) as the acceptor unit and 4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo-[1,2-b:4,5-b']dithiophene as the donor unit, named as PTZBIBDT, is developed and used as an electron-donating material in bulk-heterojunction polymer solar cells. T...

We report above-bandgap ordinary optical properties of -phase GaSe single crystal. Reference-quality pseudodielectric function E = 1 E + i 2 E and pseudorefractive index N E = n E + i k E spectra were measured by spectroscopic ellipsometry from 0.73 to 6.45 eV at room temperature for the light polarization perpendicular to the optic axis E ĉ . The spectrum exhibited several interband-transition...

The electrical characteristics of InP/In0.24Ga0.76As0.73Sb0.27/In0.53Ga0.47As double heterojunction bipolar transistor (DHBT) are investigated. The study is based on energy balance (EB) transport model and TCAD SILVACO device simulator. InP/In0.24Ga0.76As0.73Sb0.27 DHBT have a low Emitter-Base conduction band discontinuity EC and a minimum base bandgap energy EG among the entire composition ran...