Tunneling electrons from a low-temperature (5 kelvin) scanning tunneling microscope were used to control, through resonant electronic excitation, the molecular dynamics of an individual biphenyl molecule adsorbed on a silicon(100) surface. Different reversible molecular movements were selectively activated by tuning the electron energy and by selecting precise locations for the excitation inside the molecule. Both the spatial selectivity and energy dependence of the electronic control are supported by spectroscopic measurements with the scanning tunneling microscope. These experiments demonstrate the feasibility of controlling the molecular dynamics of a single molecule through the localization of the electronic excitation inside the molecule.

24Silicene is emerging as a two-dimensional material with very attractive electronic properties for a 25 wide range of applications; it is a particularly promising material for nano-electronics in silicon-26 based technology. Over the last decade, the existence and stability of silicene has been the subject 27 of much debate. Theoretical studies were the first to predict a puckered honeycomb structure with 28 electronic properties resembling those of graphene. Though these studies were for free-standing 29 silicene, experimental fabrication of silicene has been achieved so far only through epitaxial 30 growth on crystalline surfaces. Indeed, it was only in 2010 that researchers presented the first 31 experimental evidence of the formation of silicene on Ag(110) and Ag (111), which has launched 32 silicene in a similar way to graphene. This very active field has naturally led to the recent growth 33 of silicene on Ir(111), ZrB 2 (0001) and Au(110) substrates. However, the electronic properties of 34 epitaxially grown silicene on metal surfaces are influenced by the strong silicene-metal 35 interactions. This has prompted experimental studies of the growth of multi-layer silicene, though 36 the nature of its "silicene" structure remains questionable. Of course, like graphene, synthesizing 37 free-standing silicene represents the ultimate challenge. A first step towards this has been 38 reported recently through chemical exfoliation from calcium disilicide (CaSi 2 ). In this review, we 39 discuss the experimental and theoretical studies of silicene performed to date. Special attention is 40 given to different experimental studies of the electronic properties of silicene on metal substrates. 41New avenues for the growth of silicene on other substrates with different chemical characteristics 42 are presented along with foreseeable applications such as nano-devices and novel batteries. 43 44 45 46 47 111In this review paper, we will present the current state of the art of silicene. We will present new 112 avenues for the growth of silicene along with foreseeable potential applications of silicene. 113 2-Silicene growth on Ag(110) 114 6 2.1 Formation of Silicene nanoribbons on the clean Ag(110) 115 A sub-monolayer deposition of silicon on Ag(110) at room temperature (RT) results in the 116 formation of one-dimensional silicene structures [38]. The STM images clearly show isolated 117 ribbons all oriented along the (-110) direction [38-40]. It is remarkable to observe that the ribbons 118 all have exactly the same width of 1.6 nm as shown in Figs. 2.1(a) and (b). The higher resolution 119 STM image in Fig. 2.1(b) shows that the isolated Si nanoribbons (NRs) have an internal structure 120 composed of six-atom blocks aligned along the nanowires. Each block has the form of a square 121 joined to a parallelogram with a ridged profile (Fig. 2.1c). From a visual inspection of the STM 122 images, a hexagonal structure is not visible. In fact, DFT structure calculations were necessary to 123 reveal the hexagonal structure of ...

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Electron scattering at graphene edges is expected to make a crucial contribution to the electron transport in graphene nanodevices by producing quantum interferences. Atomic-scale scanning tunneling microscopy (STM) topographies of different edge structures of monolayer graphene show that the localization of the electronic density of states along the C-C bonds, a property unique to monolayer graphene, results in quantum interference patterns along the graphene carbon bond network, whose shapes depend only on the edge structure and not on the electron energy.

Phosphorene is a new 2D material composed of a single or few atomic layers of black phosphorus. Phosphorene has both an intrinsic tunable direct bandgap and high carrier mobility values, which make it suitable for a large variety of optical and electronic devices. However, the synthesis of single‐layer phosphorene is a major challenge. The standard procedure to obtain phosphorene is by exfoliation. More recently, the epitaxial growth of single‐layer phosphorene on Au(111) was investigated by molecular beam epitaxy and the obtained structure described as a blue phosphorene sheet. In the present study, large areas of high‐quality monolayer phosphorene, with a bandgap value equal to at least 0.8 eV, are synthesized on Au(111). The experimental investigations, coupled with density functional theory calculations, give evidence of two distinct phases of blue phosphorene on Au(111), instead of one as previously reported, and their atomic structures are determined.

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The scanning tunneling microscope (STM) can be used to select a particular adsorbed molecule, probe its electronic structure, dissociate the molecule by using electrons from the STM tip, and then examine the dissociation products. These capabilities are demonstrated for decaborane(14) (B(10)H(14)) molecules adsorbed on a silicon(111)-(7 x 7) surface. In addition to basic studies, such selective dissociation processes can be used in a variety of applications to control surface chemistry on the molecular scale.

Inelastic electron tunnelling excitation of propagating surface plasmon polaritons (SPPs) on a thin gold film is demonstrated. This is done by combining a scanning tunnelling microscope (STM) with an inverted optical microscope. Analysis of the leakage radiation in both the image and Fourier planes unambiguously shows that the majority (up to 99.5%) of the detected photons originate from propagating SPPs with propagation lengths of the order of 10  µm. The remaining photon emission is localized under the STM tip and is attributed to a tip-gold film coupled plasmon resonance as evidenced by the bimodal spectral distribution and enhanced emission intensity observed using a silver STM tip for excitation.