Search results for "Optoelectronics"

Theoretical characterization of the electronic structure of polymeric systems combining disilanylene and /spl pi/-conjugated units

1994

Summary form only given. Polymeric organosilicon systems are in the forefront of research, due to their intriguing properties (semiconducting behavior, photoconduction, non-linear optical properties, and thermo- and piezochromism). The fundamental skeletons of most of these polymers consist of a /spl sigma/-electron network formed by silicon-silicon bonds. Recently, polymeric organosilicon systems containing a regular alternation of a disilanylene unit and carbon /spl pi/-conjugated moiety as phenylene, ethynylene, or ethenylene have been synthesized. The purpose of this contribution is to perform a detailed study of the electronic structure of polymers containing alternated disilanylene an…

Non-linear optical spectra of excitons in polydiacetylene

1992

Abstract Adding long-range Coulomb interactions to the Su-Schrieffer-Heeger model makes it possible to investigate excitonic states in conjugated polymers. Various characteristic features due to these states as well as due to the electron-hole continuum can be found in the calculated non-linear optical susceptibilities. In particular the electroabsorption spectrum and the third harmonic generation intensity and its dependence on the system size are examined. Using only moderate interaction strength, various experiments in polydiacetylene can be interpreted in a consistent way.

<title>All-optical poling of DMABI molecules in a polymer matrix</title>

2005

Many organic compounds in solid state have nonlinear optical properties due to the orientation of the molecules in a polymer matrix. In this work, all-optical poling and second harmonic generation in a composition consisting of 1 mass% of N,N-dimethylaminobenzylidene 1,3-indandione (DMABI) compound in poly(methyl methacrylate) (PMMA) matrix were studied. Thin films were prepared by solvent casting. The 1.064-μm fundamental and 532-nm second harmonic wavelengths of a Nd:YAG laser were used. It is shown that DMABI molecules can be oriented by the method of all- optical poling, and that the process is related to the photoinduced switching between two equally stable states of the molecule.

Twisted hexaazatrianthrylene: synthesis, optoelectronic properties and near-infrared electroluminescent heterojunctions thereof

2015

The synthesis, optoelectronic properties and near-infrared electroluminescent heterojunctions of a twisted and soluble 7,8,15,16,23,24-hexaazatrianthrylene derivative are reported.

Indium Selenide Solar Cells

1981

Indium selenide photovoltaic devices are described. Transport and photovoltaic properties are discussed. Efficiencies of 6% are reported and ways of improvement are proposed.

3.5-μm bandwidth mid-infrared supercontinuum generation in a 2-cm long suspended-core chalcogenide fiber

2014

A supercontinuum source extending from 0.6 to 4.1 µm has been successfully generated in a 2-cm long As2S3 chalcogenide suspended-core fiber by means of a nJ-level 200-fs pumping at 2.5 µm.

Optical Modification of Monolayer MoS 2 : Deterministic Modification of CVD Grown Monolayer MoS 2 with Optical Pulses (Adv. Mater. Interfaces 10/2021)

2021

Progress in the Development of CdTe and CdZnTe Semiconductor Radiation Detectors for Astrophysical and Medical Applications

2009

Over the last decade, cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) wide band gap semiconductors have attracted increasing interest as X-ray and gamma ray detectors. Among the traditional high performance spectrometers based on silicon (Si) and germanium (Ge), CdTe and CdZnTe detectors show high detection efficiency and good room temperature performance and are well suited for the development of compact and reliable detection systems. In this paper, we review the current status of research in the development of CdTe and CdZnTe detectors by a comprehensive survey on the material properties, the device characteristics, the different techniques for improving the overall detector…

Exciton and multiexciton optical properties of single InAs/GaAs site-controlled quantum dots

2013

We have studied the optical properties of InAs site-controlled quantum dots (SCQDs) grown on pre-patterned GaAs substrates. Since InAs nucleates preferentially on the lithography motifs, the location of the resulting QDs is determined by the pattern, which is fabricated by local oxidation nanolithography. Optical characterization has been performed on such SCQDs to study the fundamental and excited states. At the ground state different exciton complex transitions of about 500 μeV linewidth have been identified and the fine structure splitting of the neutral exciton has been determined (≈65 μeV). The observed electronic structure covers the demands of future quantum information technologies.…

ChemInform Abstract: Tuning the Band Gap of PbCrO4Through High-Pressure: Evidence of Wide-to-Narrow Semiconductor Transitions.

2014

Commercial polycrystalline and cleaved platelets from natural PbCrO4 are studied in a diamond anvil cell at ≤ 21 GPa.