WorldCat Identities

Kemerink, M. (Martijn)

Overview
Works: 39 works in 45 publications in 1 language and 218 library holdings
Genres: Conference papers and proceedings 
Roles: Editor, Author
Classifications: QH212.S35, 502.825
Publication Timeline
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Most widely held works by M Kemerink
Scanning tunneling microscopy/spectroscopy and related techniques : 12th international conference, Eindhoven, the Netherlands by International Conference on Scanning Tunneling Microscopy/Spectroscopy and Related Techniques( Book )

7 editions published in 2003 in English and held by 179 WorldCat member libraries worldwide

"The plenary and invited presentations can be found in the printed part of the proceedings, whereas the CD contains all the accepted publications"--Preface
Scanning tunneling microscopy/spectroscopy and related techniques( Book )

1 edition published in 2003 in English and held by 2 WorldCat member libraries worldwide

Scanning tunneling spectroscopy on organic semiconductors : experiment and model( )

1 edition published in 2004 in English and held by 1 WorldCat member library worldwide

Scanning-tunneling spectroscopy expts. performed on conjugated polymer films are compared with three-dimensional numerical model calcns. for charge injection and transport. It is found that if a sufficiently sharp tip is used, the field enhancement near the tip apex leads to a significant increase in the injected current, which can amt. to more than an order of magnitude and can even change the polarity of the predominant charge carrier. We show that when charge injection from the tip into the org. material predominates, it is possible to probe the electronic properties of the interface between the org. material and a metallic electrode directly by means of tip height vs. bias voltage measurements. Thus, one can det. the alignment of the MO energy levels at the buried interface, as well as the single-particle band gap of the org. material. By comparing the single-particle energy gap and the optical absorption threshold, it is possible to obtain an est. of the exciton binding energy. In addn., our calcns. show that by using a one-dimensional model, reasonable parameters can only be extd. from z-V and I-V curves if the tip apex radius is much larger than the tip height. In all other cases, the full three-dimensional problem needs to be considered
Real-space measurement of the potential distribution inside organic semiconductors( )

1 edition published in 2002 in English and held by 1 WorldCat member library worldwide

We demonstrate that the soft nature of organic semiconductors can be exploited to directly measure the potential distribution inside such an organic layer by scanning-tunneling microscope (STM) based spectroscopy. Keeping the STM feedback system active while reducing the tip-sample bias forces the tip to penetrate the organic layer. From an analysis of the injection and bulk transport processes it follows that the tip height versus bias trace obtained in this way directly reflects the potential distribution in the organic layer
Optical detection of ballistic electrons injected by a scanning-tunneling microscope( )

1 edition published in 2001 in English and held by 1 WorldCat member library worldwide

We demonstrate a spectroscopic technique which is based on ballistic injection of minority carriers from the tip of a scanning-tunneling microscope into a semiconductor heterostructure. By analyzing the resulting electroluminescence spectrum as a function of tip-sample bias, both the injection barrier height and the carrier scattering rate in the semiconductor can be determined. This technique is complementary to ballistic electron emission spectroscopy since minority instead of majority carriers are injected, which give the opportunity to study the carrier trajectory after injection
Low-temperature scanning-tunneling microscope for luminescence measurements in high magnetic fields( )

1 edition published in 2001 in English and held by 1 WorldCat member library worldwide

We have designed and built a low-temperature (1.3–4.2 K) scanning-tunneling microscope which is capable of collecting light that is generated in the tunneling region. Light collection is done by means of two fibers whose cleaved front is in close proximity (1 mm) to the tunneling region. The whole system can be operated in high magnetic fields (11 T) without loss of optical signal strength. As a demonstration, we measured the electroluminescence spectra of an InGaAs quantum well at various temperatures. At 4.2 K, we found an electron-to-photon conversion factor that is three orders of magnitude higher than at room temperature
Scanning tunneling microscopy / 12th International Conference, STM'03 : Eindhoven, the Netherlands, 21-25 July 2003 by American Institute of Physics( )

1 edition published in 2003 in English and held by 1 WorldCat member library worldwide

Kinetic Monte Carlo simulations of organic ferroelectrics by Tim Cornelissen( )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

Ferroelectrics find broad applications, e.g. in non-volatile memories, but the switching kinetics in real, disordered, materials is still incompletely understood. Here, we develop an electrostatic model to study ferroelectric switching using 3D Monte Carlo simulations. We apply this model to the prototypical small molecular ferroelectric trialkylbenzene-1,3,5-tricarboxamide (BTA) and find good agreement between the Monte Carlo simulations, experiments, and molecular dynamics studies. Since the model lacks any explicit steric effects, we conclude that these are of minor importance. While the material is shown to have a frustrated antiferroelectric ground state, it behaves as a normal ferroelectric under practical conditions due to the large energy barrier for switching that prevents the material from reaching its ground state after poling. We find that field-driven polarization reversal and spontaneous depolarization have orders of magnitude different switching kinetics. For the former, which determines the coercive field and is relevant for data writing, nucleation occurs at the electrodes, whereas for the latter, which governs data retention, nucleation occurs at disorder-induced defects. As a result, by reducing the disorder in the system, the polarization retention time can be increased dramatically while the coercive field remains unchanged
Range and energetics of charge hopping in organic semiconductors by Hassan Abdalla( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

The recent upswing in attention for the thermoelectric properties of organic semiconductors (OSCs) adds urgency to the need for a quantitative description of the range and energetics of hopping transport in organic semiconductors under relevant circumstances, i.e., around room temperature (RT). In particular, the degree to which hops beyond the nearest neighbor must be accounted for at RT is still largely unknown. Here, measurements of charge and energy transport in doped OSCs are combined with analytical modeling to reach the univocal conclusion that variable-range hopping is the proper description in a large class of disordered OSC at RT. To obtain quantitative agreement with experiment, one needs to account for the modification of the density of states by ionized dopants. These Coulomb interactions give rise to a deep tail of trap states that is independent of the materials initial energetic disorder. Insertion of this effect into a classical Mott-type variable-range hopping model allows one to give a quantitative description of temperature-dependent conductivity and thermopower measurements on a wide range of disordered OSCs. In particular, the model explains the commonly observed quasiuniversal power-law relation between the Seebeck coefficient and the conductivity
Licht uit nul-dimensionale objecten( )

1 edition published in 2001 in English and held by 1 WorldCat member library worldwide

No abstract
Contactless charge carrier mobility measurement in organic field-effect transistors by W. S. Christian Roelofs( )

1 edition published in 2014 in English and held by 1 WorldCat member library worldwide

With the increasing performance of organic semiconductors, contact resistances become an almost fundamental problem, obstructing the accurate measurement of charge carrier mobilities. Here, a generally applicable method is presented to determine the true charge carrier mobility in an organic field-effect transistor (OFET). The method uses two additional finger-shaped gates that capacitively generate and probe an alternating current in the OFET channel. The time lag between drive and probe can directly be related to the mobility, as is shown experimentally and numerically. As the scheme does not require the injection or uptake of charges it is fundamentally insensitive to contact resistances. Particularly for ambipolar materials the true mobilities are found to be substantially larger than determined by conventional (direct current) schemes
The operational mechanism of ferroelectric-driven organic resistive switches: by M Kemerink( )

1 edition published in 2012 in English and held by 1 WorldCat member library worldwide

The availability of a reliable memory element is crucial for the fabrication of 'plastic' logic circuits. We use numerical simulations to show that the switching mechanism of ferroelectric-driven organic resistive switches is the stray field of the polarized ferroelectric phase. The stray field modulates the charge injection from a metallic electrode into the organic semiconductor, switching the diode from injection limited to space charge limited. The modeling rationalizes the previously observed exponential dependence of the on/off ratio on injection barrier height. We find a lower limit of about 50 nm for the feature size that can be used in a crossbar array, translating into a rewritable memory with an information density of the order of 1 Gb/cm2. © 2011 Elsevier B.V. All rights reserved
On the width of the recombination zone in ambipolar organic field effect transistors( )

1 edition published in 2008 in English and held by 1 WorldCat member library worldwide

The performance of organic light emitting field effect transistors is strongly influenced by the width of the recombination zone. We present an analytical model for the recombination profile. By assuming Langevin recombination, the recombination zone width W is found to be given by W=??4.34d??, with d and ?? the gate dielectric and accumulation layer thicknesses, respectively. The model compares favorably to both numerical calculations and measured surface potential profiles of an actual ambipolar device
Coulomb-blockade oscillations in a double quantum dot system( )

1 edition published in 1993 in English and held by 1 WorldCat member library worldwide

The dynamic organic p-n junction by Piotr Matyba( )

1 edition published in 2009 in English and held by 1 WorldCat member library worldwide

Static p-n junctions in inorganic semiconductors are exploited in a wide range of todays electronic appliances. Here, we demonstrate the in situ formation of a dynamic p-n junction structure within an organic semiconductor through electrochemistry. Specifically, we use scanning kelvin probe microscopy and optical probing on planar light-emitting electrochemical cells (LECs) with a mixture of a conjugated polymer and an electrolyte connecting two electrodes separated by 120 mu m. We find that a significant portion of the potential drop between the electrodes coincides with the location of a thin and distinct light-emission zone positioned andgt;30 mu m away from the negative electrode. These results are relevant in the context of a long-standing scientific debate, as they prove that electrochemical doping can take place in LECs. Moreover, a study on the doping formation and dissipation kinetics provides interesting detail regarding the electronic structure and stability of the dynamic organic p-n junction, which may be useful in future dynamic p-n junction-based devices
Many-particle effects in Be-δ-doped GaAs/Al_{x}Ga_{1-x}As quantum wells( )

1 edition published in 1998 in English and held by 1 WorldCat member library worldwide

We have performed photoluminescence (PL) and photoluminescence excitation measurements on two series of center- delta -doped p-type GaAs/Al/sub x/Ga/sub 1-x/As quantum wells, with variable well width and doping concentration. The experimental data are compared with self-consistent field calculations. The effects of exchange and correlation were found to be extremely important and various models for the hole exchange and correlation are compared with the experimental data. It is found that the model recently proposed by Bobbert et al. [P. A. Bobbert et al., Phys. Rev. B 56, 3664 (1997)] consistently describes our experimental observations. Furthermore, for well widths w>or=600 AA clear excitonic effects were observed, for hole densities as high as 12*10/sup 12/ cm/sup -2/, which is explained in terms of small spatial overlap between the screening particles and the exciton along the growth direction. In contrast to earlier work on similar samples, we found no indication for a Fermi-edge singularity in the PL spectra of our samples. Peaked structures at the high-energy side of the PL spectra are shown to arise from bulk transitions
Magneto-optical study on exciton screening in p-type AlxGa1-xAs/InyGa1-yAS quantum wells( )

1 edition published in 1997 in English and held by 1 WorldCat member library worldwide

Enhanced Electrical Conductivity of Molecularly p-Doped Poly(3-hexylthiophene) through Understanding the Correlation with Solid-State Order by Jonna Hynynen( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

Molecular p-doping of the conjugated polymer poly(3-hexylthiophene) (P3HT) with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4TCNQ) is a widely studied model system. Underlying structure property relationships are poorly understood because processing and doping are often carried out simultaneously. Here, we exploit doping from the vapor phase, which allows us to disentangle the influence of processing and doping. Through this approach, we are able to establish how the electrical conductivity varies with regard to a series of predefined structural parameters. We demonstrate that improving the degree of solid-state order, which we control through the choice of processing solvent and regioregularity, strongly increases the electrical conductivity. As a result, we achieve a value of up to 12.7 S cm( -2) for P3HT:F4TCNQ, We determine the F4TCNQ anion concentration and find that the number of (bound + mobile) charge carriers of about 10( -4) mol cm( -3) is not influenced by the degree of solid-state order. Thus, the observed increase in electrical conductivity by almost 2 orders of magnitude can be attributed to an increase in charge-carrier mobility to more than 10( -1) cm(2) V-1 s( -1). Surprisingly, in contrast to charge transport in undoped P3HT, we find that the molecular weight of the polymer does not strongly influence the electrical conductivity, which highlights the need for studies that elucidate structure property relationships of strongly doped conjugated polymers
Physical reality of the Preisach model for organic ferroelectrics by Indre Urbanaviciute( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

The Preisach model has been a cornerstone in the fields of ferromagnetism and ferroelectricity since its inception. It describes a real, non-ideal, ferroic material as the sum of a distribution of ideal hysterons. However, the physical reality of the model in ferroelectrics has been hard to establish. Here, we experimentally determine the Preisach (hysteron) distribution for two ferroelectric systems and show how its broadening directly relates to the materials morphology. We connect the Preisach distribution to measured microscopic switching kinetics that underlay the macroscopic dispersive switching kinetics as commonly observed for practical ferroelectrics. The presented results reveal that the in principle mathematical construct of the Preisach model has a strong physical basis and is a powerful tool to explain polarization switching at all time scales in different types of ferroelectrics. These insights lead to guidelines for further advancement of the ferroelectric materials both for conventional and multi-bit data storage applications
On the width of the recombination zone in ambipolar organic field effect transistors: by M Kemerink( )

1 edition published in 2008 in English and held by 1 WorldCat member library worldwide

 
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Scanning tunneling microscopy/spectroscopy and related techniques : 12th international conference, Eindhoven, the Netherlands Scanning tunneling microscopy/spectroscopy and related techniques Scanning tunneling microscopy / 12th International Conference, STM'03 : Eindhoven, the Netherlands, 21-25 July 2003
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Scanning tunneling microscopy/spectroscopy and related techniquesScanning tunneling microscopy / 12th International Conference, STM'03 : Eindhoven, the Netherlands, 21-25 July 2003
Alternative Names
Kemerink, M.

Kemerink, Martijn

Languages
English (26)