Search

Your search keyword '"Charge collection"' showing total 679 results
Start Over Descriptor "Charge collection"
679 results on '"Charge collection"'

651. Reduced Graphene Oxide/Mesoporous TiO2 Nanocomposite Based Perovskite Solar Cells.

Author

Han GS, Song YH, Jin YU, Lee JW, Park NG, Kang BK, Lee JK, Cho IS, Yoon DH, and Jung HS

Abstract

We report on reduced graphene oxide (rGO)/mesoporous (mp)-TiO2 nanocomposite based mesostructured perovskite solar cells that show an improved electron transport property owing to the reduced interfacial resistance. The amount of rGO added to the TiO2 nanoparticles electron transport layer was optimized, and their impacts on film resistivity, electron diffusion, recombination time, and photovoltaic performance were investigated. The rGO/mp-TiO2 nanocomposite film reduces interfacial resistance when compared to the mp-TiO2 film, and hence, it improves charge collection efficiency. This effect significantly increases the short circuit current density and open circuit voltage. The rGO/mp-TiO2 nanocomposite film with an optimal rGO content of 0.4 vol % shows 18% higher photon conversion efficiency compared with the TiO2 nanoparticles based perovskite solar cells.

Published
2015
Full Text
View/download PDF

652. Collection-limited theory interprets the extraordinary response of single semiconductor organic solar cells.

Author

Ray B, Baradwaj AG, Khan MR, Boudouris BW, and Alam MA

Abstract

The bulk heterojunction (BHJ) organic photovoltaic (OPV) architecture has dominated the literature due to its ability to be implemented in devices with relatively high efficiency values. However, a simpler device architecture based on a single organic semiconductor (SS-OPV) offers several advantages: it obviates the need to control the highly system-dependent nanoscale BHJ morphology, and therefore, would allow the use of broader range of organic semiconductors. Unfortunately, the photocurrent in standard SS-OPV devices is typically very low, which generally is attributed to inefficient charge separation of the photogenerated excitons. Here we show that the short-circuit current density from SS-OPV devices can be enhanced significantly (∼100-fold) through the use of inverted device configurations, relative to a standard OPV device architecture. This result suggests that charge generation may not be the performance bottleneck in OPV device operation. Instead, poor charge collection, caused by defect-induced electric field screening, is most likely the primary performance bottleneck in regular-geometry SS-OPV cells. We justify this hypothesis by: (i) detailed numerical simulations, (ii) electrical characterization experiments of functional SS-OPV devices using multiple polymers as active layer materials, and (iii) impedance spectroscopy measurements. Furthermore, we show that the collection-limited photocurrent theory consistently interprets typical characteristics of regular SS-OPV devices. These insights should encourage the design and OPV implementation of high-purity, high-mobility polymers, and other soft materials that have shown promise in organic field-effect transistor applications, but have not performed well in BHJ OPV devices, wherein they adopt less-than-ideal nanostructures when blended with electron-accepting materials.

Published
2015
Full Text
View/download PDF

653. Progress with the single-sided module prototypes for the ATLAS tracker upgrade stave

Author

Allport, P.P., Affolder, A.A., Anghinolfi, F., Bates, R., Betancourt, C., Buttar, C., Carter, J.R., Casse, G., Chen, H., Chilingarov, A., Civera, J.V., Clark, A., Colijn, A.P., Dabrowski, W., Dawson, N., DeWilde, B., Dhawan, S., Dressnandt, N., Dwužnik, M., and Eklund, L.

Subjects
*PROTOTYPES, *PHYSICS experiments, *LARGE Hadron Collider, *RADIATION, *PHOTONICS, *INTEGRATED circuits, *DETECTORS
Abstract

Abstract: The ATLAS experiment is preparing for the planned luminosity upgrade of the LHC (the super-luminous LHC or sLHC) with a programme of development for tracking able to withstand an order of greater magnitude radiation fluence and much greater hit occupancy rates than the current detector. This has led to the concept of an all-silicon tracker with an enhanced performance pixel-based inner region and short-strips for much of the higher radii. Both sub-systems employ many common technologies, including the proposed “stave” concept for integrated cooling and support. For the short-strip region, use of this integrated stave concept requires single-sided modules mounted on either side of a thin central lightweight support. Each sensor is divided into four rows of 23.82mm length strips; within each row, there are 1280 strips of 74.5μm pitch. Well over a hundred prototype sensors are being delivered by Hamamatsu Photonics (HPK) to Japan, Europe and the US. We present results of the first 20 chip ABCN25 ASIC hybrids for these sensors, results of the first prototype 5120 strip module built with 40 ABCN25 read-out ASICs, and the status of the hybrids and modules being developed for the ATLAS tracker upgrade stave programme. [Copyright &y& Elsevier]

Published
2011
Full Text
View/download PDF

654. Testing of surface properties pre-rad and post-rad of n-in-p silicon sensors for very high radiation environment

Author

Lindgren, S., Affolder, A.A., Allport, P.P., Bates, R., Betancourt, C., Bohm, J., Brown, H., Buttar, C., Carter, J.R., Casse, G., Chen, H., Chilingarov, A., Cindro, V., Clark, A., Dawson, N., DeWilde, B., Doherty, F., Dolezal, Z., Eklund, L., and Fadeyev, V.

Subjects
*SILICON diodes, *STRIP transmission lines, *PHYSICS experiments, *RADIATION injuries, *PHOTONICS, *SIGNALS & signaling
Abstract

Abstract: We are developing n+-in-p, p-bulk and n-readout, microstrip sensors as a non-inverting radiation hard silicon detector for the ATLAS Tracker Upgrade at the super LHC experiment. The surface radiation damages of the sensors fabricated by Hamamatsu Photonics are characterized on the interstrip capacitance, interstrip resistance and punch-through protection evolution. The detector should provide acceptable strip isolation, exceeding the input impedance of the signal readout chip ∼1kΩ, after the integrated luminosity of 6ab−1, which is twice the luminosity goal. [Copyright &y& Elsevier]

Published
2011
Full Text
View/download PDF

655. Testing of bulk radiation damage of n-in-p silicon sensors for very high radiation environments

Author

Hara, K., Affolder, A.A., Allport, P.P., Bates, R., Betancourt, C., Bohm, J., Brown, H., Buttar, C., Carter, J.R., Casse, G., Chen, H., Chilingarov, A., Cindro, V., Clark, A., Dawson, N., DeWilde, B., Doherty, F., Dolezal, Z., Eklund, L., and Fadeyev, V.

Subjects
*RADIATION injuries, *SILICON diodes, *SIGNAL-to-noise ratio, *STRIP transmission lines, *PHOTONICS, *PROTONS, *NEUTRONS
Abstract

Abstract: We are developing n+-in-p, p-bulk and n-readout, microstrip sensors, fabricated by Hamamatsu Photonics, as a non-inverting radiation hard silicon detector for the ATLAS tracker upgrade at the super-LHC (sLHC) proposed facility. The bulk radiation damage after neutron and proton irradiations is characterized with the leakage current, charge collection and full depletion voltage. The detectors should provide acceptable signal, signal-to-noise ratio exceeding 15, after the integrated luminosity of 6000fb−1, which is twice the sLHC integrated luminosity goal. [Copyright &y& Elsevier]

Published
2011
Full Text
View/download PDF

656. The Cryogenic Dark Matter Search: First 5-Tower Data and Improved Understanding of Ionization Collection

Author

Bailey, Catherine N.

Subjects
Astrophysics, Particle Physics, Physics, dark matter, CDMS, charge collection
Abstract

The Cryogenic Dark Matter Search (CDMS) is searching for Weakly Interacting Massive Particles (WIMPs) with cryogenic particle detectors. These detectors have the ability to discriminate between nuclear recoil candidate and electron recoil background events by collecting both phonon and ionization energy from recoils in the detector crystals. The CDMS-II experiment has completed analysis of the first data runs with 30 semiconductor detectors at the Soudan Underground Laboratory, resulting in a world leading WIMP-nucleon spin-independent cross section limit for WIMP masses above 44 GeV/c2. As CDMS aims to achieve greater WIMP sensitivity, it is necessary to increase the detector mass and discrimination between signal and background events. Incomplete ionization collection results in the largest background in the CDMS detectors as this causes electron recoil background interactions to appear as false candidate events. Two primary causes of incomplete ionization collection are surface and bulk trapping. Recent work has been focused on reducing surface trapping through the modification of fabrication methods for future detectors. Analyzing data taken with test devices has shown that hydrogen passivation of the amorphous silicon blocking layer worsens surface trapping. Additional data has shown that the iron-ion implantation used to lower the critical temperature of the tungsten transition-edge sensors causes a degradation of the ionization collection. Using selective implantation on future detectors may improve ionization collection for events near the phonon side detector surface. Bulk trapping is minimized by neutralizing ionized lattice impurities. Detector investigations at testing facilities and in situ at the experimental site have provided methods to optimize the neutralization process and monitor running conditions to maintain full ionization collection. This work details my contribution to the 5-tower data taking, monitoring, and analysis effort as well as the SuperCDMS detector development with the focus on monitoring and improving ionization collection in the detectors.

Published
2010

657. Charge Loss Correction and Inter-strip Interpolation in a High-purity Germanium Double-sided Strip Detector.

Author

Hayward, Jason P.

Subjects
High-purity Germanium, Strip Detector, Charge Collection, Position Interpolation, Gamma Ray Imaging
Abstract

Simulated filtering of a subset of the measured fast signals shown in Fig. 74(a) and 74(e). The raw signals are shown in the top row. Fast energies on adjacent strips are determined from peak-to-peak measurements of the shaped fast signals (bottom row).

Published
2008

658. Three dimensional indium-tin-oxide nanorod array for charge collection in dye-sensitized solar cells.

Author

Lee B, Guo P, Li SQ, Buchholz DB, and Chang RP

Abstract

In this article, we report the design, fabrication, characterization, and simulation of three-dimensional (3D) dye-sensitized solar cells (DSSCs), using ordered indium-tin-oxide (ITO) nanorod (NR) arrays as the photoanode, and compare them with conventional planar (2D) DSSCs. The ITO NR array used in the 3D cell greatly improves its performance by providing shorter electron pathways and reducing the recombination rate of the photogenerated electrons. We observed a 10-20% enhancement of the energy conversion efficiency, primarily due to an increased short circuit current. This finding supports the concept of using 3D photoanodes with optically transparent and conducting nanorods for the enhancement of the energy-harvesting devices that require short charge collection distance without sacrificing the optical thickness. Thus, unlike the conventional solar cell structure, the functions for photon collection and charge transport are decoupled to allow for improved cell designs.

Published
2014
Full Text
View/download PDF

659. A framework for modeling the detailed optical response of thick, multiple segment, large format sensors for precision astronomy applications

Author

Rasmussen, Andrew, Antilogus, Pierre, Astier, Pierre, Claver, Chuck, Doherty, Peter, Dubois-Felsmann, Gregory, Gilmore, Kirk, Kahn, Steven, Kotov, Ivan, Lupton, Robert, O, Paul, Nomerotski, Andrei, Ritz, Steve, and Stubbs, Christopher William

Subjects
CCDs, charge collection, drift fields, flat field distortion, pixel size variation, imaging nonlinearities
Abstract

Near-future astronomical survey experiments, such as LSST, possess system requirements of unprecedented fidelity that span photometry, astrometry and shape transfer. Some of these requirements flow directly to the array of science imaging sensors at the focal plane. Availability of high quality characterization data acquired in the course of our sensor development program has given us an opportunity to develop and test a framework for simulation and modeling that is based on a limited set of physical and geometric effects. In this paper we describe those models, provide quantitative comparisons between data and modeled response, and extrapolate the response model to predict imaging array response to astronomical exposure. The emergent picture departs from the notion of a fixed, rectilinear grid that maps photo-conversions to the potential well of the channel. In place of that, we have a situation where structures from device fabrication, local silicon bulk resistivity variations and photo-converted carrier patterns still accumulating at the channel, together influence and distort positions within the photosensitive volume that map to pixel boundaries. Strategies for efficient extraction of modeling parameters from routinely acquired characterization data are described. Methods for high fidelity illumination/image distribution parameter retrieval, in the presence of such distortions, are also discussed. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only., Astronomy

Published
2014
Full Text
View/download PDF

660. Polovodičové struktury, metoda nábojového sběru

Author

Špinka, Jiří, Čudek, Pavel, Golda, Martin, Špinka, Jiří, Čudek, Pavel, and Golda, Martin

Abstract

Práce pojednává o studiu struktur polovodivého křemíku. Popisuje vlastnosti tohoto prvku a vytvoření polovodiče typu P a N, dále se zabývá typy poruch krystalické mřížky. Zabývá se popisem metod sledování poruch v polovodiči, stanovení vlastností polovodičů tj. metodou EBIC, EBIV a CC, které jsou využívány k analýze polovodičových součástek a materiálů. Zjišťování vlastností křemíkových součástek probíhá pomoci generace nosičů náboje ve vzorku, vloženého do komory rastrovacího elektronového mikroskopu dopadajícími vyskoenergiovými elektrony a následným sběrem naindukovaného náboje na PN přechodu. Pomocí dat získaných metodou EBIC a CC byly vyhodnoceny difúzní délka a doba života elektronů., This thesis treats about semiconducting silicon structures. It describes the characteristics of the element and creation of P and N type of semiconductor and discusses about different types of faults in the crystal lattice. It deals with the description of methods for monitoring faults in semiconductor ie. determining the properties of semiconductors via EBIC, EBIV and CC methods, which are used for analysis of semiconductor devices and materials. Determining the properties of silicon components is being done by generation of charge carriers in the sample loaded in chamber of the scanning electron microscope by high energy electrons. Bellow the sample surface is being generated an electric charge which is being collected by probes. Using this data obtained by EBIC and CC were evaluated diffusion length and lifetime of electrons.

661. Polovodičové struktury, metoda nábojového sběru

Author

Špinka, Jiří, Čudek, Pavel, Golda, Martin, Špinka, Jiří, Čudek, Pavel, and Golda, Martin

Abstract

Práce pojednává o studiu struktur polovodivého křemíku. Popisuje vlastnosti tohoto prvku a vytvoření polovodiče typu P a N, dále se zabývá typy poruch krystalické mřížky. Zabývá se popisem metod sledování poruch v polovodiči, stanovení vlastností polovodičů tj. metodou EBIC, EBIV a CC, které jsou využívány k analýze polovodičových součástek a materiálů. Zjišťování vlastností křemíkových součástek probíhá pomoci generace nosičů náboje ve vzorku, vloženého do komory rastrovacího elektronového mikroskopu dopadajícími vyskoenergiovými elektrony a následným sběrem naindukovaného náboje na PN přechodu. Pomocí dat získaných metodou EBIC a CC byly vyhodnoceny difúzní délka a doba života elektronů., This thesis treats about semiconducting silicon structures. It describes the characteristics of the element and creation of P and N type of semiconductor and discusses about different types of faults in the crystal lattice. It deals with the description of methods for monitoring faults in semiconductor ie. determining the properties of semiconductors via EBIC, EBIV and CC methods, which are used for analysis of semiconductor devices and materials. Determining the properties of silicon components is being done by generation of charge carriers in the sample loaded in chamber of the scanning electron microscope by high energy electrons. Bellow the sample surface is being generated an electric charge which is being collected by probes. Using this data obtained by EBIC and CC were evaluated diffusion length and lifetime of electrons.

662. Polovodičové struktury, metoda nábojového sběru

Author

Špinka, Jiří, Čudek, Pavel, Špinka, Jiří, and Čudek, Pavel

Abstract

Práce pojednává o studiu struktur polovodivého křemíku. Popisuje vlastnosti tohoto prvku a vytvoření polovodiče typu P a N, dále se zabývá typy poruch krystalické mřížky. Zabývá se popisem metod sledování poruch v polovodiči, stanovení vlastností polovodičů tj. metodou EBIC, EBIV a CC, které jsou využívány k analýze polovodičových součástek a materiálů. Zjišťování vlastností křemíkových součástek probíhá pomoci generace nosičů náboje ve vzorku, vloženého do komory rastrovacího elektronového mikroskopu dopadajícími vyskoenergiovými elektrony a následným sběrem naindukovaného náboje na PN přechodu. Pomocí dat získaných metodou EBIC a CC byly vyhodnoceny difúzní délka a doba života elektronů., This thesis treats about semiconducting silicon structures. It describes the characteristics of the element and creation of P and N type of semiconductor and discusses about different types of faults in the crystal lattice. It deals with the description of methods for monitoring faults in semiconductor ie. determining the properties of semiconductors via EBIC, EBIV and CC methods, which are used for analysis of semiconductor devices and materials. Determining the properties of silicon components is being done by generation of charge carriers in the sample loaded in chamber of the scanning electron microscope by high energy electrons. Bellow the sample surface is being generated an electric charge which is being collected by probes. Using this data obtained by EBIC and CC were evaluated diffusion length and lifetime of electrons.

663. Polovodičové struktury, metoda nábojového sběru

Author

Špinka, Jiří, Čudek, Pavel, Špinka, Jiří, and Čudek, Pavel

Abstract

Práce pojednává o studiu struktur polovodivého křemíku. Popisuje vlastnosti tohoto prvku a vytvoření polovodiče typu P a N, dále se zabývá typy poruch krystalické mřížky. Zabývá se popisem metod sledování poruch v polovodiči, stanovení vlastností polovodičů tj. metodou EBIC, EBIV a CC, které jsou využívány k analýze polovodičových součástek a materiálů. Zjišťování vlastností křemíkových součástek probíhá pomoci generace nosičů náboje ve vzorku, vloženého do komory rastrovacího elektronového mikroskopu dopadajícími vyskoenergiovými elektrony a následným sběrem naindukovaného náboje na PN přechodu. Pomocí dat získaných metodou EBIC a CC byly vyhodnoceny difúzní délka a doba života elektronů., This thesis treats about semiconducting silicon structures. It describes the characteristics of the element and creation of P and N type of semiconductor and discusses about different types of faults in the crystal lattice. It deals with the description of methods for monitoring faults in semiconductor ie. determining the properties of semiconductors via EBIC, EBIV and CC methods, which are used for analysis of semiconductor devices and materials. Determining the properties of silicon components is being done by generation of charge carriers in the sample loaded in chamber of the scanning electron microscope by high energy electrons. Bellow the sample surface is being generated an electric charge which is being collected by probes. Using this data obtained by EBIC and CC were evaluated diffusion length and lifetime of electrons.

664. Polovodičové struktury, metoda nábojového sběru

Author

Špinka, Jiří, Čudek, Pavel, Špinka, Jiří, and Čudek, Pavel

Abstract

Práce pojednává o studiu struktur polovodivého křemíku. Popisuje vlastnosti tohoto prvku a vytvoření polovodiče typu P a N, dále se zabývá typy poruch krystalické mřížky. Zabývá se popisem metod sledování poruch v polovodiči, stanovení vlastností polovodičů tj. metodou EBIC, EBIV a CC, které jsou využívány k analýze polovodičových součástek a materiálů. Zjišťování vlastností křemíkových součástek probíhá pomoci generace nosičů náboje ve vzorku, vloženého do komory rastrovacího elektronového mikroskopu dopadajícími vyskoenergiovými elektrony a následným sběrem naindukovaného náboje na PN přechodu. Pomocí dat získaných metodou EBIC a CC byly vyhodnoceny difúzní délka a doba života elektronů., This thesis treats about semiconducting silicon structures. It describes the characteristics of the element and creation of P and N type of semiconductor and discusses about different types of faults in the crystal lattice. It deals with the description of methods for monitoring faults in semiconductor ie. determining the properties of semiconductors via EBIC, EBIV and CC methods, which are used for analysis of semiconductor devices and materials. Determining the properties of silicon components is being done by generation of charge carriers in the sample loaded in chamber of the scanning electron microscope by high energy electrons. Bellow the sample surface is being generated an electric charge which is being collected by probes. Using this data obtained by EBIC and CC were evaluated diffusion length and lifetime of electrons.

665. Polovodičové struktury, metoda nábojového sběru

Author

Špinka, Jiří, Čudek, Pavel, Golda, Martin, Špinka, Jiří, Čudek, Pavel, and Golda, Martin

Abstract

Práce pojednává o studiu struktur polovodivého křemíku. Popisuje vlastnosti tohoto prvku a vytvoření polovodiče typu P a N, dále se zabývá typy poruch krystalické mřížky. Zabývá se popisem metod sledování poruch v polovodiči, stanovení vlastností polovodičů tj. metodou EBIC, EBIV a CC, které jsou využívány k analýze polovodičových součástek a materiálů. Zjišťování vlastností křemíkových součástek probíhá pomoci generace nosičů náboje ve vzorku, vloženého do komory rastrovacího elektronového mikroskopu dopadajícími vyskoenergiovými elektrony a následným sběrem naindukovaného náboje na PN přechodu. Pomocí dat získaných metodou EBIC a CC byly vyhodnoceny difúzní délka a doba života elektronů., This thesis treats about semiconducting silicon structures. It describes the characteristics of the element and creation of P and N type of semiconductor and discusses about different types of faults in the crystal lattice. It deals with the description of methods for monitoring faults in semiconductor ie. determining the properties of semiconductors via EBIC, EBIV and CC methods, which are used for analysis of semiconductor devices and materials. Determining the properties of silicon components is being done by generation of charge carriers in the sample loaded in chamber of the scanning electron microscope by high energy electrons. Bellow the sample surface is being generated an electric charge which is being collected by probes. Using this data obtained by EBIC and CC were evaluated diffusion length and lifetime of electrons.

672. Recovery of Semiconductor and Defect Properties from Charge-Collection Measurements

Author

Donolato, C.

Subjects
Diffusion Length, Semi conductor Characterization, Image Contrast, Carrier Recombination, Charge Collection, Life Sciences, Electron Beam Induced Current, Crystal Defects
Abstract

This paper discusses the modeling of the measurements which are performed with the charge-collection, or Electron Beam Induced Current (EBIC) technique of the scanning electron microscope, and the use of the related theoretical results for recovering bulk and local recombination properties of semi conductors. A general description of different EBIC measurements can be given on the basis of the notion of charge-collection probability 𝝋(r) in the device being examined. This function can be calculated by solving a stationary diffusion equation and the induced current results from the convolution of 𝝋(r) with the generation function of the electron beam. According to this approach, EBIC experiments give information about 𝝋 or the essential semiconductor or defect parameters upon which 𝝋 is dependent. The more usual procedures to recover this information from actual measurements are reviewed and some new possibilities are examined.

Published
1988

673. Recent Developments in Electrical Microcharacterization Using the Charge Collection Mode of the Scanning Electron Microscope

Author

Holt, D. B. and Lesniak, M.

Subjects
Electron beam induced voltage (EBIV), Image processing, Microplasmas, Charge collection, β-conductivity, Biology, Dislocation contrast, Electron beam induced current (EBIC)
Abstract

There are six distinguishable types of charge collection (CC) signal. Consequently specially designed CC detection systems are needed to obtain e.g. true EBIC and EBIV measurements and make quantitative electrical microcharacterization possible. EBIC and EBIV can arise from fields due to barriers such as p-n junctions or due to changes in doping e.g. p to p+. Materials, defect and device parameters are calculable from these signals. Hot-cold stages are important for temperature dependence studies of contrast, for improving signal to noise ratios and reducing leakage currents. Image processing and pattern recognition methods are vital for rapidly locating and evaluating the information in CC micrographs of large scale circuits. Some recent applications of these techniques to junctions and Schottky barriers in devices, to dislocations and grain boundaries, to microplasmas and to the location of defects in large scale intergration (LSI) devices are presented.

Published
1985

674. Charge collection in M-S-M cadmium telluride detectors

Author

L. V. Maslova, S.M. Ryvkin, A.T. Akobirova, O. A. Matveev, and A.Kh. Khusainov

Subjects
semiconductor counters, cadmium compounds, Materials science, charge collection, band bending, Analytical chemistry, 02 engineering and technology, 01 natural sciences, photovoltaic effects, photovoltage, 0103 physical sciences, 010306 general physics, metal semiconductor metal structures, business.industry, Detector, dark current, resolution, Charge (physics), 021001 nanoscience & nanotechnology, Cadmium telluride photovoltaics, Semiconductor detector, electric field, Band bending, II VI semiconductors, [PHYS.HIST]Physics [physics]/Physics archives, I V characteristics, Optoelectronics, 0210 nano-technology, business, Dark current
Abstract

The metal-semiconductor-metal (MSM) structure often used for cadmium telluride radiation detectors has been studied for etched and mechanically polished material. The band bending at the interfaces has been determined by looking at the spectral dependence of the photo-voltage and the I-V characteristics. An analysis of the electric field for a MSM, CdTe device shows that slower charge collection and, hence, poorer resolution than expected for a p-i-n detector, is obtained. Also the dark current is at best determined only by the resistivity of the material rather than by a barrier.

Published
1977
Full Text
View/download PDF

675. The Versatility of Scanning Electron Microscopy in Thin Film Device Analysis

Author

Drake, D. J., Hawkins, W. G., and Anderson, R. W.

Subjects
charging, charge collection, thin films, voltage contrast, transistors, Biology, Electron channeling
Abstract

The versatility of scanning electron microscopy is shown for many stages of fabrication of thin film transistor driver matrices for actively addressed liquid crystal displays. Electron channeling and Schottky barrier charge collection modes allow rapid assessment of silicon crystal quality. The secondary electron mode allows examination of conductor lead crossover integrity. A form of voltage contrast is used on the completed array to monitor performance of the array prior to liquid crystal filling.

Published
1987

676. Charge Collection in Hybrid Perovskite Solar Cells: Relation to the Nanoscale Elemental Distribution

Author

Bjoern Niesen, Tara Nietzold, Volker Rose, Michael Stuckelberger, Christophe Ballif, Genevieve N. Hall, David P. Fenning, Mariana I. Bertoni, Bradley West, and Jérémie Werner

Subjects
Imagination, Chemical substance, media_common.quotation_subject, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, law.invention, Optics, law, Homogeneity (physics), Solar cell, Electrical and Electronic Engineering, Nanoscopic scale, perovskite, media_common, degradation, methylammonium lead iodide (MAPI), X-ray beam-induced current (XBIC), business.industry, Chemistry, Charge collection, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Synchrotron, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, solar cell, Optoelectronics, X-ray fluorescence (XRF), Photonics, 0210 nano-technology, business, Science, technology and society
Abstract

Unveiling the correlation between elemental composition, Fermi-level splitting, and charge collection in perovskite solar cells (PSCs) when exposed to different environments is crucial to understanding the origin of defects. This will enable defect engineering to achieve high-performance and long-lasting PSCs. In this paper, we measured, for the first time, the spatial distribution and charge-collection efficiency at the nanoscale by synchrotron-based X-ray fluorescence (XRF) and X-ray beam-induced current (XBIC) with subgrain resolution, and we observe a correlation between Pb/I ratio and charge-collection efficiency. In contrast with other thin-film solar cells, PSCs are highly sensitive to ambient conditions (atmosphere and illumination). As the XRF and XBIC measurements were conducted in vacuum under an X-ray source illumination, the impact of measurement conditions on the cells needs to be taken into account. Furthermore, necessary conditions for quantification of XRF/XBIC measurements, such as film homogeneity, are not fulfilled in the case of PSCs. Therefore, we will discuss fundamentals of XRF/XBIC measurements of PSCs that will enable reliable, quantitative, high-resolution measurements of elemental distribution and charge collection.

677. Diamond sensors for future high energy experiments

Author

Bachmair, Felix

Subjects
Radiation hardness, Physics::Instrumentation and Detectors, Charge collection, Particle physics, 3D sensors, CVD diamond, 7. Clean energy, Diamond particle detector
Abstract

With the planned upgrade of the LHC to High-Luminosity-LHC [1], the general purpose experiments ATLAS and CMS are planning to upgrade their innermost tracking layers with more radiation tolerant technologies. Chemical Vapor Deposition CVD diamond is one such technology. CVD diamond sensors are an established technology as beam condition monitors in the highest radiation areas of all LHC experiments. The RD42-collaboration at CERN is leading the effort to use CVD diamond as a material for tracking detectors operating in extreme radiation environments. An overview of the latest developments from RD42 is presented including the present status of diamond sensor production, a study of pulse height dependencies on incident particle flux and the development of 3D diamond sensors., Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 831, ISSN:0168-9002, ISSN:1872-9576, Proceedings of the 10th International “Hiroshima” Symposium on the Development and Application of Semiconductor Tracking Detectors

678. Nanohole Structuring for Improved Performance of Hydrogenated Amorphous Silicon Photovoltaics

Author

Tonio Buonassisi, Michael Stuckelberger, Gizem Nogay, Ahmed Al-Obeidi, Jeffrey C. Grossman, and Eric Johlin

Subjects
Amorphous silicon, Materials science, charge collection, 02 engineering and technology, engineering.material, amorphous silicon, 010402 general chemistry, nanohole, 01 natural sciences, nanostructuring, chemistry.chemical_compound, Coating, Photovoltaics, Etching (microfabrication), General Materials Science, business.industry, Photovoltaic system, Energy conversion efficiency, 021001 nanoscience & nanotechnology, 0104 chemical sciences, photovoltaics, chemistry, efficiency, thin-film solar cells, engineering, Optoelectronics, Quantum efficiency, 0210 nano-technology, business, Layer (electronics)
Abstract

While low hole mobilities limit the current collection and efficiency of hydrogenated amorphous silicon (a-Si:H) photovoltaic devices, attempts to improve mobility of the material directly have stagnated. Herein, we explore a method of utilizing nanostructuring of a-Si:H devices to allow for improved hole collection in thick absorber layers. This is achieved by etching an array of 150 nm diameter holes into intrinsic a-Si:H and then coating the structured material with p-type a-Si:H and a conformal zinc oxide transparent conducting layer. The inclusion of these nanoholes yields relative power conversion efficiency (PCE) increases of ∼45%, from 7.2 to 10.4% PCE for small area devices. Comparisons of optical properties, time-of-flight mobility measurements, and internal quantum efficiency spectra indicate this efficiency is indeed likely occurring from an improved collection pathway provided by the nanostructuring of the devices. Finally, we estimate that through modest optimizations of the design and fabrication, PCEs of beyond 13% should be obtainable for similar devices.

679. Impact of low-dose electron irradiation on n+p silicon strip sensors

Author

CMS Collaboration, Adam, W., Bachmair, Felix, Becker, R., Bäni, Lukas, Di Calafiori, Diogo R., Casal, Bruno, Djambazov, Lubomir, Donegà, Mauro, Dünser, Marc, Eller, Philipp, Grab, Christophorus, Hits, Dmitry, Horisberger, Urs, Hoss, Jan, Kasieczka, Gregor, Lustermann, Werner, Mangano, Boris, Marionneau, Matthieu, Martinez Ruiz del Arbol, Pablo, Masciovecchio, Mario, Perrozzi, Luca, Roeser, U., Rossini, Marco, Starodumov, Andrey, Takahashi, Maiko, and Wallny, Rainer

Subjects
Radiation damage, Surface damage, Charge collection, 7. Clean energy, Silicon strip sensors
Abstract

The response of n+p silicon strip sensors to electrons from a 90Sr source was measured using a multi-channel read-out system with 25 ns sampling time. The measurements were performed over a period of several weeks, during which the operating conditions were varied. The sensors were fabricated by Hamamatsu Photonics on 200 μm thick float-zone and magnetic-Czochralski silicon. Their pitch was 80 μm, and both p-stop and p-spray isolation of the n+ strips were studied. The electrons from the 90Sr source were collimated to a spot with a full-width-at-half-maximum of 2 mm at the sensor surface, and the dose rate in the SiO2 at the maximum was about 50 Gy(SiO2)/d. After only a few hours of making measurements, significant changes in charge collection and charge sharing were observed. Annealing studies, with temperatures up to 80 °C and annealing times of 18 h showed that the changes can only be partially annealed. The observations can be qualitatively explained by the increase of the positive oxide-charge density due to the ionization of the SiO2 by the radiation from the β source. TCAD simulations of the electric field in the sensor for different oxide-charge densities and different boundary conditions at the sensor surface support this explanation. The relevance of the measurements for the design of n+p strip sensors is discussed., Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 803, ISSN:0168-9002, ISSN:1872-9576

Catalog

Books, media, physical & digital resources
See catalog results