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Poly(3-alkylthiophene)s show unexpected second-order nonlinear optical response

Deckers, S. (author), Vandendriessche, S. (author), Cornelis, D. (author), Monnaie, F. (author), Koeckelberghs, G. (author), Asselberghs, I. (author), Verbiest, T. (author), Van der Veen, M.A. (author)

Regioregular poly(3-hexylthiophene)s with chain lengths varying from 5 to 100 monomers are synthesized. Poly(3-hexylthiophene)s show in solution an unexpectedly significant second-order nonlinear optical response. The increase in transition dipole moment upon oligomerisation causes the significant second-order nonlinear optical response.

journal article 2014

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Acoustic effects on nonlinear optical processes

Deckers, S. (author), Van Steerteghem, Nick (author), Glorieux, Christ (author), Verbiest, Thierry (author), van der Veen, M.A. (author)

We studied the effects of two types of ultrasonic waves, shear waves and longitudinal waves, using two nonlinear optical techniques, second-harmonic generation and hyper-Rayleigh scattering. Since shear waves hardly propagate in liquids, their influence on molecules at the interface between a surface and a liquid was studied using second...

conference paper 2016

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Second harmonic generation microscopy reveals hidden polar organization in fluoride doped MIL-53(Fe)

Markey, K. (author), Putzeys, T. (author), Horcajada, P. (author), Devic, T. (author), Guillou, N. (author), Wübbenhorst, M. (author), Van Cleuvenbergen, S. (author), Verbiest, T. (author), De Vos, D.E. (author), Van der Veen, M.A. (author)

Polar metal–organic frameworks have potential applications as functional non-linear optical, piezoelectric, pyroelectric and ferroelectric materials. Using second harmonic generation microscopy we found that fluoride doping of the microporous iron(III) terephthalate MOF MIL-53(Fe) induces a polar organization in its structure, which was not...

journal article 2016

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Emergence of Nonlinear Optical Activity by Incorporation of a Linker Carrying the p-Nitroaniline Motif in MIL-53 Frameworks

Markey, Karen (author), Krüger, Martin (author), Seidler, Tomasz (author), Reinsch, Helge (author), Verbiest, Thierry (author), De Vos, Dirk E. (author), Champagne, Benoît (author), Stock, Norbert (author), van der Veen, M.A. (author)

p-Nitroaniline presents the typical motif of a second-order nonlinear optically (NLO) active molecule. However, because of its crystallization in an antiparallel and hence centrosymmetric structure, the NLO activity is lost. In this contribution, the p-nitroaniline motif was built successfully into the MIL-53 metal-organic framework. More...

journal article 2017

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Morphology and structure of ZIF-8 during crystallisation measured by dynamic angle-resolved second harmonic scattering

Van Cleuvenbergen, Stijn (author), Smith, Zachary J. (author), Deschaume, Olivier (author), Bartic, Carmen (author), Wachsmann-Hogiu, Sebastian (author), Verbiest, Thierry (author), van der Veen, M.A. (author)

Recent developments in nonlinear optical light scattering techniques have opened a window into morphological and structural characteristics for a variety of supramolecular systems. However, for the study of dynamic processes, the current way of measuring is often too slow. Here we present an alternative measurement scheme suitable for...

journal article 2018

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Integrated impedance bridge for absolute capacitance measurements at cryogenic temperatures and finite magnetic fields

Verbiest, G.J. (author), Janssen, H. (author), Xu, D. (author), Ge, X. (author), Goldsche, M. (author), Sonntag, J. (author), Khodkov, T. (author), Banszerus, L. (author), Von Den Driesch, N. (author)

We developed an impedance bridge that operates at cryogenic temperatures (down to 60 mK) and in perpendicular magnetic fields up to at least 12 T. This is achieved by mounting a GaAs HEMT amplifier perpendicular to a printed circuit board containing the device under test and thereby parallel to the magnetic field. The measured amplitude and...

journal article 2019

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Phonon scattering at kinks in suspended graphene

Dolleman, R.J. (author), Blanter, Y.M. (author), van der Zant, H.S.J. (author), Steeneken, P.G. (author), Verbiest, G.J. (author)

Recent experiments have shown surprisingly large thermal time constants in suspended graphene ranging from 10 to 100 ns in drums with a diameter ranging from 2 to 7 μm. The large time constants and their scaling with diameter points toward a thermal resistance at the edge of the drum. However, an explanation of the microscopic origin of this...

journal article 2020

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Optical absorption sensing with dual-spectrum silicon LEDs in SOI-CMOS technology

Dutta, S. (author), Steeneken, P.G. (author), Verbiest, G.J. (author)

Silicon p-n junction diodes emit low-intensity, broad-spectrum light near 1120 nm in forward bias and between 400-900 nm in reverse bias (avalanche). For the first time, we experimentally achieve optical absorption sensing of pigment in solution with silicon micro LEDs designed in a standard silicon-on-insulator CMOS technology. By driving a...

conference paper 2020

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Nonequilibrium thermodynamics of acoustic phonons in suspended graphene

Dolleman, R.J. (author), Verbiest, G.J. (author), Blanter, Y.M. (author), van der Zant, H.S.J. (author), Steeneken, P.G. (author)

Recent theory has predicted large temperature differences between the in-plane [longitudinal (LA) and transverse (TA)] and out-of-plane [flexural (ZA)] acoustic phonon baths in locally heated suspended graphene. To verify these predictions, and their implications for understanding the nonequilibrium thermodynamics of two-dimensional (2D)...

journal article 2020

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Nanoelectromechanical sensors based on suspended 2D materials

Lemme, Max C. (author), Wagner, Stefan (author), Lee, Kangho (author), Fan, Xuge (author), Verbiest, G.J. (author), Wittmann, Sebastian (author), Lukas, Sebastian (author), Dolleman, R.J. (author), Niklaus, Frank (author), van der Zant, H.S.J. (author), Duesberg, Georg S. (author), Steeneken, P.G. (author)

The unique properties and atomic thickness of two-dimensional (2D) materials enable smaller and better nanoelectromechanical sensors with novel functionalities. During the last decade, many studies have successfully shown the feasibility of using suspended membranes of 2D materials in pressure sensors, microphones, accelerometers, and mass...

review 2020

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Tunable coupling of two mechanical resonators by a graphene membrane

Verbiest, G.J. (author), Goldsche, M. (author), Sonntag, J. (author), Khodkov, T. (author), von den Driesch, N. (author), Buca, D. (author), Stampfer, C. (author)

Coupled nanomechanical resonators are interesting for both fundamental studies and practical applications as they offer rich and tunable oscillation dynamics. At present, the mechanical coupling in such systems is often mediated by a fixed geometry, such as a joint clamping point of the resonators or a displacement-dependent force. Here we...

journal article 2021

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Nonlinear optical probes of nucleation and crystal growth: recent progress and future prospects

Dok, Ahmet R. (author), Legat, Thibaut (author), de Coene, Yovan (author), van der Veen, M.A. (author), Verbiest, T. (author), Van Cleuvenbergen, Stijn (author)

In situexperimental studies have been key in uncovering the often elusive pathways of nucleation and crystal growth. In the field of material science and medicine this offers the prospect of controlling crystallization processes to fight disease or tailor materials towards specific applications. To further advance this quest there is a need...

review 2021

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Acoustic subsurface-atomic force microscopy: Three-dimensional imaging at the nanoscale

Sharahi, Hossein J. (author), Janmaleki, Mohsen (author), Tetard, Laurene (author), Kim, Seonghwan (author), Sadeghian, Hamed (author), Verbiest, G.J. (author)

The development of acoustic subsurface atomic force microscopy, which promises three-dimensional imaging with single-digit nanometer resolution by the introduction of ultrasound actuations to a conventional atomic force microscope, has come a long way since its inception in the early 1990s. Recent advances provide a quantitative understanding...

journal article 2021

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Ultrasound Pulse Emission Spectroscopy Method to Characterize Xylem Conduits in Plant Stems

Dutta, S. (author), Chen, Zhiyi (author), Kaiser, Elias (author), Malcolm Matamoros, Priscilla (author), Steeneken, P.G. (author), Verbiest, G.J. (author)

Although it is well known that plants emit acoustic pulses under drought stress, the exact origin of the waveform of these ultrasound pulses has remained elusive. Here, we present evidence for a correlation between the characteristics of the waveform of these pulses and the dimensions of xylem conduits in plants. Using a model that relates the...

journal article 2022

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Optical sensing of chlorophyll(in) with dual-spectrum Si LEDs in SOI-CMOS technology

Dutta, S. (author), Steeneken, P.G. (author), Verbiest, G.J. (author)

Small and low-cost chlorophyll sensors are popular in agricultural sector and food-quality control.Combining such sensors with silicon CMOS electronics is challenged by the absence of silicon-integrated light-sources.We experimentally achieve optical absorption sensing of chlorophyll based pigments with silicon (Si) micro light-emitting...

journal article 2022

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Self-Sealing Complex Oxide Resonators

Lee, M. (author), Robin, M.P. (author), Guis, R.H. (author), Filippozzi, U. (author), Shin, D. (author), van Thiel, T.C. (author), Paardekooper, Stijn P. (author), Renshof, Johannes R. (author), van der Zant, H.S.J. (author), Caviglia, A. (author), Verbiest, G.J. (author), Steeneken, P.G. (author)

Although 2D materials hold great potential for next-generation pressure sensors, recent studies revealed that gases permeate along the membrane-surface interface, necessitating additional sealing procedures. In this work, we demonstrate the use of free-standing complex oxides as self-sealing membranes that allow the reference cavity beneath...

journal article 2022

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Ultrathin Piezoelectric Resonators Based on Graphene and Free-Standing Single-Crystal BaTiO₃

Lee, M. (author), Renshof, Johannes R. (author), van Zeggeren, K.J. (author), Houmes, M.J.A. (author), Lesne, E.L. (author), Siskins, M. (author), van Thiel, T.C. (author), Guis, R.H. (author), van Blankenstein, M.R. (author), Verbiest, G.J. (author), Caviglia, A. (author), van der Zant, H.S.J. (author), Steeneken, P.G. (author)

Suspended piezoelectric thin films are key elements enabling high-frequency filtering in telecommunication devices. To meet the requirements of next-generation electronics, it is essential to reduce device thickness for reaching higher resonance frequencies. Here, the high-quality mechanical and electrical properties of graphene electrodes...

journal article 2022

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Avalanche-mode Si light-emitting transistor for narrow-band emission near 760 nm

Dutta, S. (author), Hueting, Raymond J.E. (author), Verbiest, G.J. (author)

We report an avalanche-mode light-emitting transistor (AMLET) in silicon (Si), based on a lateral bipolar junction, which emits light near 760 nm optical wavelength with a record low bandwidth of 38 nm. The AMLET, designed in a CMOS-compatible silicon-on-insulator (SOI) photonics platform, is optically confined within a 0.21 ∼\μ m thick SOI...

journal article 2022

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Fabry-Pérot resonant avalanche-mode silicon LEDs for tunable narrow-band emission

Dutta, S. (author), Verbiest, G.J. (author)

We report on the effect of Fabry-Pérot (FP) resonance on hot-carrier electroluminescence (EL) spectra and the optical power efficiencies of silicon (Si) avalanche-mode (AM) LEDs in the wavelength range from 500 nm to 950 nm. The LEDs, fabricated in a silicon-on-insulator photonics technology, consist of symmetric p-n junctions placed within a 0...

journal article 2022

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Ultra-sensitive graphene membranes for microphone applications

Baglioni, G. (author), Pezone, R. (author), Vollebregt, S. (author), Cvetanović Zobenica, Katarina (author), Spasenović, Marko (author), Todorović, Dejan (author), Liu, Hanqing (author), Verbiest, G.J. (author), van der Zant, H.S.J. (author), Steeneken, P.G. (author)

Microphones exploit the motion of suspended membranes to detect sound waves. Since the microphone performance can be improved by reducing the thickness and mass of its sensing membrane, graphene-based microphones are expected to outperform state-of-the-art microelectromechanical (MEMS) microphones and allow further miniaturization of the...

journal article 2023