Angle-dependent carrier transmission probability in graphene p-n junctions is investigated. Using electrostatic doping from buried gates, p-n junctions are formed along graphene channels that are patterned to form different angles with the junction. A peak in the junction resistance is observed, which becomes pronounced with angle. This angular dependence is observed for junctions made on both exfoliated and CVD-grown graphene and is consistent with the theoretically predicted dependence of transmission probability on incidence angle.

is, graphene, transition metal dichalcogenides (TMDs), [ 2,3 ] topological insulators, [ 4 ] h-BN [ 5 ] and h-AlN, [ 6 ] as well the recent phosphorene, [ 7 ] silicene, [ 8 ] and germanene [ 9 ] provide the ability to control the channel thickness at atomic level. This characteristic translates into improved gate control over the channel barrier and into reduced short-channel effects, thus paving the way toward ultimate miniaturization and new device concepts. Recently, 2D transition metal dichalcogenides, have proven to be promising candidates for electronics and optoelectronic applications. [10][11][12][13][14][15][16] From a pioneering perspective, the availability of TMDs with different work functions and band structures guarantees a great potential for band gap engineering of heterostructures. These systems are fundamentally different and more fl exible than traditional heterostructures composed of conventional semiconductors. In particular, due to the weak interlayer interaction, a TMD molecular layer grows from the beginning with its own lattice constant forming an interface with reduced amount of defects. The relaxed lattice matching condition permits to combine almost any layered material and create artifi cial heterojunctions with designed band alignment. 2D heterostructures

The rapid cadence of MOSFET scaling is stimulating the development of new technologies and accelerating the introduction of new semiconducting materials as silicon alternative. In this context, 2D materials with a unique layered structure have attracted tremendous interest in recent years, mainly motivated by their ultra-thin body nature and unique optoelectronic and mechanical properties. The development of scalable synthesis techniques is obviously a fundamental step towards the development of a manufacturable technology. Metal-organic chemical vapor deposition has recently been used for the synthesis of large area TMDs, however, an important milestone still needs to be achieved: the ability to precisely control the number of layers and surface uniformity at the nano-to micro-length scale to obtain an atomically flat, self-passivated surface. In this work, we explore various fundamental aspects involved in the chemical vapor deposition process and we provide important insights on the layer-dependence of epitaxial MoS film's structural properties. Based on these observations, we propose an original method to achieve a layer-controlled epitaxy of wafer-scale TMDs.

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