Search results for "optoelectronic"

Corrigendum to “Design of compensated multiport waveguide junctions considering mechanization effects” [AEUE – Int J Electron Commun, 69 (1) (2015), …

2015

Quasifractal planar microstrip resonators for microwave circuits

1999

We propose a new shape for microwave planar circuits using the self-similarity of the fractal geometry. This new shape allows the generation of numerous resonant frequencies for this microwave planar resonator due to the surface's encasing. The resonant frequency assessment can be useful for the concept of filters or wide frequency band matching loads as examples, without consuming circuit surface. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 21: 433–436, 1999.

Electrical-optical characterization of multijunction solar cells under 2000X concentration

2014

In the framework of the FAE "Fotovoltaico ad Alta Efficienza" ("High Efficiency Photovoltaic") Research Project (PO FESR Sicilia 2007/2013 4.1.1.1), we have performed electrical and optical characterizations of commercial InGaP/InGaAs/Ge triple-junction solar cells (1 cm2) mounted on a prototype HCPV module, installed in Palermo (Italy). This system uses a reflective optics based on rectangular off-axis parabolic mirror with aperture 45×45 cm2 leading to a geometrical concentration ratio of 2025. In this study, we report the I-V curve measured under incident power of about 700 W/m2 resulting in an electrical power at maximum point (PMP) of 41.4 W. We also investigated the optical properties…

Towards roll-to-roll fabrication of electronics, optics and optoelectronics for smart and intelligent packaging

2004

Embedding of optoelectrical, optical, and electrical functionalities into low-cost products like packages and printed matter can be used to increase their information content. These functionalities make also possible the realization of new type of entertaining, impressive or guiding effects on the product packages and printed matter. For these purposes, components like displays, photodetectors, light sources, solar cells, battery elements, diffractive optical elements, lightguides, electrical conductors, resistors, transistors, switching elements etc. and their integration to functional modules are required. Additionally, the price of the components for low-end products has to be in cent sc…

Label-free wavelength and phase detection based SMS fiber immunosensors optimized with cladding etching

2018

The performance of E-SMS (Etched Singlemode-Multimode-Singlemode) optical fiber structures as immunosensors has been assessed by the implementation of antibody/antigen immunoassays. Through this procedure it has been proven that E-SMS structures are effective and suitable optical platforms for label-free biosensing. Using the phase shift and tracking the wavelength response it was found that the fabricated E-SMS devices exhibited limits of detection (LOD) down up to concentrations of 0.2mg/L of antigens in solution. This was achieved by coating the E-SMS with an antibody-based biolayer (goat IgG) that is able to determine the presence of anti-goat IgG antigen. Both a wavelength detection an…

Investigation of amorphous oxide film-electrolyte junctions by AC techniques

1992

Current AC (alternating current) techniques are used often to characterize the energetics at a semiconducting solid phase/electrolyte interface. For thin layers having a strongly disordered or amorphous structure (such as oxide-passive layers anodically grown on valve metals), interpretative models currently used for crystalline semiconductors may produce misleading data. A new interpretation of the admittance data, based on recent models for amorphous semiconductors (a-Sc) Schottky barriers, is presented for passive films of Nb, W and Ti. The physical bases of the model are presented as well as its advantages and disadvantages. The new theory views the solid/electrolyte interface more sati…

Colloidal Nanoplatelet/Conducting Polymer Hybrids: Excitonic And Material Properties

2016

WOS:000370678700053 Here we present the first account of conductive polymer/colloidal nanoplatelet hybrids. For this, we developed DEH-PPV-based polymers with two different anchor groups (sulfide and amine) acting as surfactants for CdSe nanoplatelets, which are atomically flat semiconductor nanocrystals. Hybridization of the polymers with the nanoplatelets in the solution phase was observed to cause strong photoluminescence quenching in both materials. Through steady-state photoluminescence and excitation spectrum measurements, photoluminescence quenching was shown to result from dominant exciton dissociation through charge transfer at the polymer/nanoplatelet interfaces that possess a sta…

Gain, detuning, and radiation patterns of nanoparticle optical antennas

2008

International audience; For their capability to localize and redirect electromagnetic field, metal nanoparticles have been recently viewed as efficient nanoantenna operating in the optical regime. In this article, we experimentally investigated the optical responses of coupled gold antenna pairs and measured the critical parameters defining antenna characteristics: resonant frequencies and bandwidths, detuning and gains, and radiation patterns.

Know your full potential: Quantitative Kelvin probe force microscopy on nanoscale electrical devices

2018

In this study we investigate the influence of the operation method in Kelvin probe force microscopy (KPFM) on the measured potential distribution. KPFM is widely used to map the nanoscale potential distribution in operating devices, e.g., in thin film transistors or on cross sections of functional solar cells. Quantitative surface potential measurements are crucial for understanding the operation principles of functional nanostructures in these electronic devices. Nevertheless, KPFM is prone to certain imaging artifacts, such as crosstalk from topography or stray electric fields. Here, we compare different amplitude modulation (AM) and frequency modulation (FM) KPFM methods on a reference s…

Compact 20-pass thin-disk amplifier insensitive to thermal lensing

2019

We present a multi-pass amplifier which passively compensates for distortions of the spherical phase front occurring in the active medium. The design is based on the Fourier transform propagation which makes the output beam parameters insensitive to variation of thermal lens effects in the active medium. The realized system allows for 20 reflections on the active medium and delivers a small signal gain of 30 with M$^2$ = 1.16. Its novel geometry combining Fourier transform propagations with 4f-imaging stages as well as a compact array of adjustable mirrors allows for a layout with a footprint of 400 mm x 1000 mm.