wileyonlinelibrary.comGraphene, [ 11 ] a one-atom thick zero band gap semiconductor has allowed the development of new electronic device schemes such as the graphene-barristor, [ 12 ] the graphene-vertical-fi eld-effecttransistor (VFET), [13][14][15][16] and the graphenebase hot electron transistor. [ 17 ] In organic electronics, graphene can be an ideal choice to use as the injector (or source) electrode for a VFET since its Fermi level, its corresponding work function and its available low density of states (DOS) [ 18 ] can all be easily modulated, providing a tunable energy barrier which eventually controls the device operation. In addition, the electric fi eld produced by a gate electrode will extend into the organic semiconductor, as the monolayer thickness of graphene is insuffi cient to fully screen it. [ 13,19 ] In order to increase the performance of organic thin fi lm transistors (OTFT) compared with the inorganic counterparts, a unique vertical architecture with a molecular semiconductor (C 60 ) was fi rst demonstrated using a thin and rough (with a roughness comparable to the thickness) metal electrode. [ 20 ] A clear advantage of the vertical over the lateral organic transistor geometry is that the channel length is controlled by the thickness of the organic layer and the devices can be downsized in both the lateral and the vertical directions. In the case of a perforated metallic source electrode, the electric fi eld can directly access the metal/organic interface which causes the energy level realignment (similar to the band bending in inorganic semiconductor) in the organic semiconductor. Although Ma and Yang have reported a large on/off current ratio (≈10 6 ), the high DOS and the fi xed work function of the metallic electrode (injector) limits its application to a few organic semiconductors. [ 20 ] Later on, Liu et al. introduced a carbon nanotube-based source electrode with low DOS in organic VFETs for a wide range of organic semiconductors. [ 21 ] Carbon nanotubes allow new mechanisms for transistor operation such as the tuning of the gate modulated energy barrier. Graphene, similar to carbon nanotubes in its electrical and mechanical properties, has additional advantages over them due to the large-scale availability (chemical vapor deposition (CVD)-grown graphene) of chemically inert high quality 2D surfaces. [ 14,22 ] On the other hand, fullerene (C 60 ) is one of the most widely studied molecular semiconductors [ 2,5,20,[23][24][25] and a common choice as an active media for transistors. C 60 has an energy gap ( E g = 1.7 eV), between its highest occupied molecular orbital Gate-Controlled Energy Barrier at a Graphene/Molecular Semiconductor JunctionSubir Parui , * Luca Pietrobon , David Ciudad , Saül Vélez , Xiangnan Sun , Fèlix Casanova , Pablo Stoliar , and Luis E. Hueso * The formation of an energy-barrier at a metal/molecular semiconductor junction is a universal phenomenon which limits the performance of many molecular semiconductor-based electronic devices, from fi eld-effect trans...

The energetics of metal/molecular semiconductor interfaces plays a fundamental role in organic electronics, determining the performance of very diverse devices. So far, information about the energy level alignment has been most commonly gained by spectroscopy techniques that typically require experimental conditions far from the real device operation. Here we demonstrate that a simple three-terminal device allows the acquisition of spectroscopic information about the metal/molecule energy alignment in real operative condition. As a proof of principle, we employ the proposed device to measure the energy barrier height between different clean metals and C 60 molecules and we recover typical results from photoemission spectroscopy. The device is designed to inject a hot electron current directly into the molecular level devoted to charge transport, disentangling the contributions of both the interface and the bulk to the device total resistance, with important implications for spintronics and low-temperature physics.

Graphene has been predicted to develop a magnetic moment by proximity effect when placed on a ferromagnetic film, a promise that could open exciting possibilities in the fields of spintronics and magnetic data recording. In this work, the interplay between the magnetoresistance of graphene and the magnetization of an underlying ferromagnetic insulating film is studied in detail. A clear correlation between both magnitudes is observed but through a careful modeling of the magnetization and the weak localization measurements, that such correspondence can be explained by the effects of the magnetic stray fields arising from the ferromagnetic insulator is found. The results emphasize the complexity arising at the interface between magnetic and 2D materials.

We developed a one-transistor one-resistor cell composed of one TiO 2 -based resistive switching (RS) device and one ZnO-based thin-film transistor (TFT). We study the electric characteristics of each component individually, and their interplay when both work together. We explored the direct control of bipolar RS devices, using our TFTs to drive current in both directions. We also report striking power implications when we swap the terminals of the RS device. The target of our work is the introduction of RS devices in large-area electronic (LAE) circuits. In this context, RS devices can be beneficial regarding functionality and energy consumption, when compared to other ways to introduce memory cells in LAE circuits.

L. E. Hueso and co‐workers observe magnetic field lines (as imaged by electron holography) arising from a ferromagnetic insulating substrate which crosses a graphene device. On page 6295, they show how the changes in the weak localisation of the graphene are created by the magnetic domain distribution and cannot be attributed to other more exotic effects, such as magnetic proximity.