Mixed Functional Siloxane Monolayers Prepared via Chemical Vapor Deposition.

Functionalizing surfaces with self-assembled monolayers (SAMs) allows to efficiently bind bioreceptors, for instance, by bio-orthogonal click reactions, which is useful in biosensor fabrication. Control of the bioreceptor concentration on the surface can be achieved by coating an SAM mixture consisting of a functional SAM, which binds the bioreceptor, and a nonfunctional SAM for dilution. In this work, a novel vapor-based coating approach for the preparation of mixed SAM coatings is presented.

Peak Broadening in Photoelectron Spectroscopy of Amorphous Polymers: The Leading Role of the Electrostatic Landscape.

The broadening in photoelectron spectra of polymers can be attributed to several factors, such as light source spread, spectrometer resolution, the finite lifetime of the hole state, and solid-state effects. Here, for the first time, we set up a computational protocol to assess the peak broadening induced for both core and valence levels by solid-state effects in four amorphous polymers by using a combination of density functional theory, many-body perturbation theory, and classical polarizable embedding. We show that intrinsic local inhomogeneities in the electrostatic environment induce a Gaussian broadening of 0.

Mean Free Path of Electrons in Organic Photoresists for Extreme Ultraviolet Lithography in the Kinetic Energy Range 20-450 eV.

The blur caused by the nonzero mean free path of electrons in photoresists exposed by extreme ultraviolet lithography has detrimental consequences on patterning resolution, but its effect is difficult to quantify experimentally. So far, most mean free path calculations use the dielectric formalism, which is an approximation valid in the optical limit and fails at low kinetic energy. In this work, we used a modified substrate-overlayer technique that exploited the attenuation of the Si 2p core level originating specifically from the native silicon dioxide to evaluate the attenuation of electrons traveling through 2 and 4 nm of photoresist overlayers to provide a close estimation of the inelastic mean free path relevant for photoresist lithography patterning and for electron microscopy.

Interface-Engineered Organic Near-Infrared Photodetector for Imaging Applications.

We report a high-speed low dark current near-infrared (NIR) organic photodetector (OPD) on a silicon substrate with amorphous indium gallium zinc oxide (a-IGZO) as the electron transport layer (ETL). In-depth understanding of the origin of dark current is obtained using an elaborate set of characterization techniques, including temperature-dependent current-voltage measurements, current-based deep-level transient spectroscopy (Q-DLTS), and transient photovoltage decay measurements. These characterization results are complemented by energy band structures deduced from ultraviolet photoelectron spectroscopy.

Conductivity Enhancement in Transition Metal Dichalcogenides: A Complex Water Intercalation and Desorption Mechanism.

The complexity of the water adsorption-desorption mechanism at the interface of transition metal dichalcogenides (TMDs) and its impact on their current transport are not yet fully understood. Here, our work investigates the swift intercalation of atmospheric adsorbates at the TMD and sapphire interface and between two TMD monolayers and probes its influence on their electrical properties. The adsorbates consist mainly of hydroxyl-based (OH) species in the subsurface region suggesting persistent water intercalation even under vacuum conditions, as determined by time-of-flight-secondary ion mass spectrometry (ToF-SIMS) and scanning tunneling microscopy (STM).