22 research outputs found

    Atomic White-Out: Enabling Atomic Circuitry Through Mechanically Induced Bonding of Single Hydrogen Atoms to a Silicon Surface

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    We report the mechanically induced formation of a silicon-hydrogen covalent bond and its application in engineering nanoelectronic devices. We show that using the tip of a non-contact atomic force microscope (NC-AFM), a single hydrogen atom could be vertically manipulated. When applying a localized electronic excitation, a single hydrogen atom is desorbed from the hydrogen passivated surface and can be transferred to the tip apex as evidenced from a unique signature in frequency shift curves. In the absence of tunnel electrons and electric field in the scanning probe microscope junction at 0 V, the hydrogen atom at the tip apex is brought very close to a silicon dangling bond, inducing the mechanical formation of a silicon-hydrogen covalent bond and the passivation of the dangling bond. The functionalized tip was used to characterize silicon dangling bonds on the hydrogen-silicon surface, was shown to enhance the scanning tunneling microscope (STM) contrast, and allowed NC-AFM imaging with atomic and chemical bond contrasts. Through examples, we show the importance of this atomic scale mechanical manipulation technique in the engineering of the emerging technology of on-surface dangling bond based nanoelectronic devices.Comment: 9 pages (including references and Supplementary Section), 8 figures (5 in the main text, 3 in Supplementary

    New fabrication technique for highly sensitive qPlus sensor with well-defined spring constant

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    A new technique for the fabrication of highly sensitive qPlus sensor for atomic force microscopy (AFM) is described. Focused ion beam was used to cut then weld onto a bare quartz tuning fork a sharp micro-tip from an electrochemically etched tungsten wire. The resulting qPlus sensor exhibits high resonance frequency and quality factor allowing increased force gradient sensitivity. Its spring constant can be determined precisely which allows accurate quantitative AFM measurements. The sensor is shown to be very stable and could undergo usual UHV tip cleaning including e-beam and field evaporation as well as in-situ STM tip treatment. Preliminary results with STM and AFM atomic resolution imaging at 4.5 K4.5\,K of the silicon Si(111)−7×7Si(111)-7\times 7 surface are presented.Comment: 5 pages, 3 figure

    Binary Atomic Silicon Logic

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    It has long been anticipated that the ultimate in miniature circuitry will be crafted of single atoms. Despite many advances made in scanned probe microscopy studies of molecules and atoms on surfaces, challenges with patterning and limited thermal stability have remained. Here we make progress toward those challenges and demonstrate rudimentary circuit elements through the patterning of dangling bonds on a hydrogen terminated silicon surface. Dangling bonds sequester electrons both spatially and energetically in the bulk band gap, circumventing short circuiting by the substrate. We deploy paired dangling bonds occupied by one movable electron to form a binary electronic building block. Inspired by earlier quantum dot-based approaches, binary information is encoded in the electron position allowing demonstration of a binary wire and an OR gate

    Single Electron Dynamics of an Atomic Silicon Quantum Dot on the H-Si(100) 2x1 Surface

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    Here we report the direct observation of single electron charging of a single atomic Dangling Bond (DB) on the H-Si(100) 2x1 surface. The tip of a scanning tunneling microscope is placed adjacent to the DB to serve as a single electron sensitive charge-detector. Three distinct charge states of the dangling bond, positive, neutral, and negative, are discerned. Charge state probabilities are extracted from the data, and analysis of current traces reveals the characteristic single electron charging dynamics. Filling rates are found to decay exponentially with increasing tip-DB separation, but are not a function of sample bias, while emptying rates show a very weak dependence on tip position, but a strong dependence on sample bias, consistent with the notion of an atomic quantum dot tunnel coupled to the tip on one side and the bulk silicon on the other.Comment: 7 pages, 6 figure

    Electronically induced manipulation of single molecules adsorbed on semiconductor surfaces : towards bi-molecular devices

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    L’objectif de cette thĂšse est d’explorer le contrĂŽle de processus Ă©lectroniquement induits dans diverses molĂ©cules fonctionnalisĂ©es adsorbĂ©es sur la surface du Si(100). Ce travail s’inscrit dans le contexte des nanosciences molĂ©culaires et a Ă©tĂ© rĂ©alisĂ© Ă  l’aide d’un microscope Ă  effet tunnel (STM) Ă  basse tempĂ©rature (9K). Nous avons utilisĂ© une approche combinant Ă©tude statistique et modĂ©lisation thĂ©orique afin de pouvoir explorer la physique des divers processus observĂ©s. Cette thĂšse dĂ©bute par l’étude de la molĂ©cule d’hexaphĂ©nyle benzĂšne (HPB) dont les phĂ©nyles latĂ©raux permettent un dĂ©couplage Ă©lectronique entre la molĂ©cule et la surface du silicium. GrĂące Ă  cet effet, nous avons pu contrĂŽler la diffusion directive et rĂ©versible de la molĂ©cule d’HPB physisorbĂ©e le long des marches de type SA Ă  la surface du Si(100)−2×1 Ă  travers un processus combinant l’action des Ă©lectrons tunnels et celle du champ Ă©lectrostatique induit par la pointe du STM. Ces premiers rĂ©sultats ont permis d’envisager l’étude d’un couple de molĂ©cules de tĂ©traphĂ©nyles porphyrines mĂ©talliques adsorbĂ©es Ă  la surface du Si(100)−2×1. Il s’agit de NiTPP et de CuTPP qui, comme pour l’HPB, possĂšdent des cycles phĂ©nyles latĂ©raux. Plusieurs conformations d’adsorption de ces deux molĂ©cules ont Ă©tĂ© caractĂ©risĂ©es et leurs rĂ©ponses Ă  des excitations Ă©lectroniques Ă©tudiĂ©es. Ceci nous a permis, pour la molĂ©cule de NiTPP, d’aboutir au contrĂŽle de l’activation rĂ©versible d’un bistable intra-molĂ©culaire en dĂ©pit de la chimisorption partielle de la molĂ©cule sur le silicium. L’étude de la molĂ©cule de CuTPP, quant Ă  elle, montre des courbes de conductance I(V) en forme d’hystĂ©rĂ©sis associĂ©es Ă  des changements rĂ©versibles de conformations rĂ©alisant ainsi une fonction mĂ©moire. DĂšs lors, nous avons pu Ă©tudier la co-adsorption des molĂ©cules de NiTPP et de CuTPP sur le Si(100) afin de rĂ©aliser un binĂŽme molĂ©culaire. Divers couples de molĂ©cules ont pu ĂȘtre Ă©tudiĂ©s. Sur l’un d’entre eux, nous avons pu activer des processus d’excitations inter-molĂ©culaires en excitant Ă©lectroniquement l’une des molĂ©cules afin d’observer un changement de conformation de la seconde molĂ©cule du binĂŽme. Ce rĂ©sultat rĂ©alise ainsi le contrĂŽle Ă©lectronique d’un dispositif bi-molĂ©culaire en s’affranchissant des processus Ă©lectroniques induits via le substrat. Enfin, Ă  titre de perspective, ce travail de thĂšse prĂ©sente un procĂ©dĂ© novateur permettant le contrĂŽle local de l’hydrogĂ©nation de la surface de Si(100). Ceci est rĂ©alisĂ© grĂące Ă  la passivation de la pointe du STM par l’hydrogĂšne molĂ©culaire Ă  9K. Les Ă©lectrons tunnels sont ensuite utilisĂ©s pour induire la dissociation intra-dimer des molĂ©cules d’H2 sur la surface du Si(100). Cette technique peut ĂȘtre envisagĂ©e pour la passivation du Si(100) ou pour agir localement sur des circuits molĂ©culaires.The objective of this thesis is to explore the control of electronically induced processes in various functionalized molecules adsorbed on the surface of silicon (100). In the context of molecular nanoscience, this work has been carried out using a scanning tunneling microscope operating at low temperature (9K). We used an approach combining statistical study and theoretical modelling in order to explore the physics of the various observed processes. This thesis begins with the study of the Hexaphenylbenzene (HPB) molecule for which the lateral phenyl rings enable the molecule-silicon surface electronic decoupling. Thanks to this effect, we could achieve a directive and reversible diffusion control of physisorbed HPB molecules along the SA silicon step edge through a process combining the joint actions of tunnel electrons and the local STM tip induced electrostatic field. These first results allowed considering the study of a couple of metaltetraphenyl porphyrin molecules adsorbed on the Si(100)-2x1 surface. Similarly to the HPB molecules, the two chosen metalloporphyrins: NiTPP and CuTPP, have lateral phenyl rings. Several adsorption conformations for these molecules were characterized and their response to electronic excitation has been studied. In the case of NiTPP, this led to the control of the reversible activation of an intra-molecular bistable despite the partial chemisorption of the molecule on the silicon surface. As for CuTPP molecule, our study revealed hysteresis behavior on the I(V) conduction curves associated with reversible conformation changes which represents the realization of a memory function. Following the study of each molecule apart, we performed the co-adsorption of the two molecules on the Si(100) surface to study molecular pairs. Various pairs of molecules have been studied. On one of them, we were able to activate an inter-molecular excitation transfer process by locally exciting one molecule and observing a conformation change of the second molecule of the pair. This result thus shows the electronic control of a bi-molecular device getting rid of substrate mediated electronic process. Finally, as a perspective, this thesis presents a novel technique allowing the controlled local hydrogenation of the Si(100) surface. This is achieved thanks to the passivation of the STM tip by molecular hydrogen at 9K. The tunnel electrons are then used to induce the intra-dimer dissociative adsorption of H2 molecules on the Si(100) surface. This technique could be considered for the passivation of Si(100) or to locally modify molecular circuits

    Manipulations électroniquement induites de molécules individuelles à la surface de semiconducteurs : vers les dispositifs bi-moléculaires

    No full text
    The objective of this thesis is to explore the control of electronically induced processes in various functionalized molecules adsorbed on the surface of silicon (100). In the context of molecular nanoscience, this work has been carried out using a scanning tunneling microscope operating at low temperature (9K). We used an approach combining statistical study and theoretical modelling in order to explore the physics of the various observed processes. This thesis begins with the study of the Hexaphenylbenzene (HPB) molecule for which the lateral phenyl rings enable the molecule-silicon surface electronic decoupling. Thanks to this effect, we could achieve a directive and reversible diffusion control of physisorbed HPB molecules along the SA silicon step edge through a process combining the joint actions of tunnel electrons and the local STM tip induced electrostatic field. These first results allowed considering the study of a couple of metaltetraphenyl porphyrin molecules adsorbed on the Si(100)-2x1 surface. Similarly to the HPB molecules, the two chosen metalloporphyrins: NiTPP and CuTPP, have lateral phenyl rings. Several adsorption conformations for these molecules were characterized and their response to electronic excitation has been studied. In the case of NiTPP, this led to the control of the reversible activation of an intra-molecular bistable despite the partial chemisorption of the molecule on the silicon surface. As for CuTPP molecule, our study revealed hysteresis behavior on the I(V) conduction curves associated with reversible conformation changes which represents the realization of a memory function. Following the study of each molecule apart, we performed the co-adsorption of the two molecules on the Si(100) surface to study molecular pairs. Various pairs of molecules have been studied. On one of them, we were able to activate an inter-molecular excitation transfer process by locally exciting one molecule and observing a conformation change of the second molecule of the pair. This result thus shows the electronic control of a bi-molecular device getting rid of substrate mediated electronic process. Finally, as a perspective, this thesis presents a novel technique allowing the controlled local hydrogenation of the Si(100) surface. This is achieved thanks to the passivation of the STM tip by molecular hydrogen at 9K. The tunnel electrons are then used to induce the intra-dimer dissociative adsorption of H2 molecules on the Si(100) surface. This technique could be considered for the passivation of Si(100) or to locally modify molecular circuits.L’objectif de cette thĂšse est d’explorer le contrĂŽle de processus Ă©lectroniquement induits dans diverses molĂ©cules fonctionnalisĂ©es adsorbĂ©es sur la surface du Si(100). Ce travail s’inscrit dans le contexte des nanosciences molĂ©culaires et a Ă©tĂ© rĂ©alisĂ© Ă  l’aide d’un microscope Ă  effet tunnel (STM) Ă  basse tempĂ©rature (9K). Nous avons utilisĂ© une approche combinant Ă©tude statistique et modĂ©lisation thĂ©orique afin de pouvoir explorer la physique des divers processus observĂ©s. Cette thĂšse dĂ©bute par l’étude de la molĂ©cule d’hexaphĂ©nyle benzĂšne (HPB) dont les phĂ©nyles latĂ©raux permettent un dĂ©couplage Ă©lectronique entre la molĂ©cule et la surface du silicium. GrĂące Ă  cet effet, nous avons pu contrĂŽler la diffusion directive et rĂ©versible de la molĂ©cule d’HPB physisorbĂ©e le long des marches de type SA Ă  la surface du Si(100)−2×1 Ă  travers un processus combinant l’action des Ă©lectrons tunnels et celle du champ Ă©lectrostatique induit par la pointe du STM. Ces premiers rĂ©sultats ont permis d’envisager l’étude d’un couple de molĂ©cules de tĂ©traphĂ©nyles porphyrines mĂ©talliques adsorbĂ©es Ă  la surface du Si(100)−2×1. Il s’agit de NiTPP et de CuTPP qui, comme pour l’HPB, possĂšdent des cycles phĂ©nyles latĂ©raux. Plusieurs conformations d’adsorption de ces deux molĂ©cules ont Ă©tĂ© caractĂ©risĂ©es et leurs rĂ©ponses Ă  des excitations Ă©lectroniques Ă©tudiĂ©es. Ceci nous a permis, pour la molĂ©cule de NiTPP, d’aboutir au contrĂŽle de l’activation rĂ©versible d’un bistable intra-molĂ©culaire en dĂ©pit de la chimisorption partielle de la molĂ©cule sur le silicium. L’étude de la molĂ©cule de CuTPP, quant Ă  elle, montre des courbes de conductance I(V) en forme d’hystĂ©rĂ©sis associĂ©es Ă  des changements rĂ©versibles de conformations rĂ©alisant ainsi une fonction mĂ©moire. DĂšs lors, nous avons pu Ă©tudier la co-adsorption des molĂ©cules de NiTPP et de CuTPP sur le Si(100) afin de rĂ©aliser un binĂŽme molĂ©culaire. Divers couples de molĂ©cules ont pu ĂȘtre Ă©tudiĂ©s. Sur l’un d’entre eux, nous avons pu activer des processus d’excitations inter-molĂ©culaires en excitant Ă©lectroniquement l’une des molĂ©cules afin d’observer un changement de conformation de la seconde molĂ©cule du binĂŽme. Ce rĂ©sultat rĂ©alise ainsi le contrĂŽle Ă©lectronique d’un dispositif bi-molĂ©culaire en s’affranchissant des processus Ă©lectroniques induits via le substrat. Enfin, Ă  titre de perspective, ce travail de thĂšse prĂ©sente un procĂ©dĂ© novateur permettant le contrĂŽle local de l’hydrogĂ©nation de la surface de Si(100). Ceci est rĂ©alisĂ© grĂące Ă  la passivation de la pointe du STM par l’hydrogĂšne molĂ©culaire Ă  9K. Les Ă©lectrons tunnels sont ensuite utilisĂ©s pour induire la dissociation intra-dimer des molĂ©cules d’H2 sur la surface du Si(100). Cette technique peut ĂȘtre envisagĂ©e pour la passivation du Si(100) ou pour agir localement sur des circuits molĂ©culaires

    Contribution a l'etude de l'effet Staebler et Wronski dans le silicium amorphe hydrogene

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    SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

    Manipulations électroniquement induites de molécules individuelles à la surface de semiconducteurs (vers les dispositifs bi-moléculaires)

    No full text
    L objectif de cette thĂšse est d explorer le contrĂŽle de processus Ă©lectroniquement induits dans diverses molĂ©cules fonctionnalisĂ©es adsorbĂ©es sur la surface du Si(100). Ce travail s inscrit dans le contexte des nanosciences molĂ©culaires et a Ă©tĂ© rĂ©alisĂ© Ă  l aide d un microscope Ă  effet tunnel (STM) Ă  basse tempĂ©rature (9K). Nous avons utilisĂ© une approche combinant Ă©tude statistique et modĂ©lisation thĂ©orique afin de pouvoir explorer la physique des divers processus observĂ©s. Cette thĂšse dĂ©bute par l Ă©tude de la molĂ©cule d hexaphĂ©nyle benzĂšne (HPB) dont les phĂ©nyles latĂ©raux permettent un dĂ©couplage Ă©lectronique entre la molĂ©cule et la surface du silicium. GrĂące Ă  cet effet, nous avons pu contrĂŽler la diffusion directive et rĂ©versible de la molĂ©cule d HPB physisorbĂ©e le long des marches de type SA Ă  la surface du Si(100) 2.1 Ă  travers un processus combinant l action des Ă©lectrons tunnels et celle du champ Ă©lectrostatique induit par la pointe du STM. Ces premiers rĂ©sultats ont permis d envisager l Ă©tude d un couple de molĂ©cules de tĂ©traphĂ©nyles porphyrines mĂ©talliques adsorbĂ©es Ă  la surface du Si(100) 2.1. Il s agit de NiTPP et de CuTPP qui, comme pour l HPB, possĂšdent des cycles phĂ©nyles latĂ©raux. Plusieurs conformations d adsorption de ces deux molĂ©cules ont Ă©tĂ© caractĂ©risĂ©es et leurs rĂ©ponses Ă  des excitations Ă©lectroniques Ă©tudiĂ©es. Ceci nous a permis, pour la molĂ©cule de NiTPP, d aboutir au contrĂŽle de l activation rĂ©versible d un bistable intra-molĂ©culaire en dĂ©pit de la chimisorption partielle de la molĂ©cule sur le silicium. L Ă©tude de la molĂ©cule de CuTPP, quant Ă  elle, montre des courbes de conductance I(V) en forme d hystĂ©rĂ©sis associĂ©es Ă  des changements rĂ©versibles de conformations rĂ©alisant ainsi une fonction mĂ©moire. DĂšs lors, nous avons pu Ă©tudier la co-adsorption des molĂ©cules de NiTPP et de CuTPP sur le Si(100) afin de rĂ©aliser un binĂŽme molĂ©culaire. Divers couples de molĂ©cules ont pu ĂȘtre Ă©tudiĂ©s. Sur l un d entre eux, nous avons pu activer des processus d excitations inter-molĂ©culaires en excitant Ă©lectroniquement l une des molĂ©cules afin d observer un changement de conformation de la seconde molĂ©cule du binĂŽme. Ce rĂ©sultat rĂ©alise ainsi le contrĂŽle Ă©lectronique d un dispositif bi-molĂ©culaire en s affranchissant des processus Ă©lectroniques induits via le substrat. Enfin, Ă  titre de perspective, ce travail de thĂšse prĂ©sente un procĂ©dĂ© novateur permettant le contrĂŽle local de l hydrogĂ©nation de la surface de Si(100). Ceci est rĂ©alisĂ© grĂące Ă  la passivation de la pointe du STM par l hydrogĂšne molĂ©culaire Ă  9K. Les Ă©lectrons tunnels sont ensuite utilisĂ©s pour induire la dissociation intra-dimer des molĂ©cules d H2 sur la surface du Si(100). Cette technique peut ĂȘtre envisagĂ©e pour la passivation du Si(100) ou pour agir localement sur des circuits molĂ©culaires.The objective of this thesis is to explore the control of electronically induced processes in various functionalized molecules adsorbed on the surface of silicon (100). In the context of molecular nanoscience, this work has been carried out using a scanning tunneling microscope operating at low temperature (9K). We used an approach combining statistical study and theoretical modelling in order to explore the physics of the various observed processes. This thesis begins with the study of the Hexaphenylbenzene (HPB) molecule for which the lateral phenyl rings enable the molecule-silicon surface electronic decoupling. Thanks to this effect, we could achieve a directive and reversible diffusion control of physisorbed HPB molecules along the SA silicon step edge through a process combining the joint actions of tunnel electrons and the local STM tip induced electrostatic field. These first results allowed considering the study of a couple of metaltetraphenyl porphyrin molecules adsorbed on the Si(100)-2x1 surface. Similarly to the HPB molecules, the two chosen metalloporphyrins: NiTPP and CuTPP, have lateral phenyl rings. Several adsorption conformations for these molecules were characterized and their response to electronic excitation has been studied. In the case of NiTPP, this led to the control of the reversible activation of an intra-molecular bistable despite the partial chemisorption of the molecule on the silicon surface. As for CuTPP molecule, our study revealed hysteresis behavior on the I(V) conduction curves associated with reversible conformation changes which represents the realization of a memory function. Following the study of each molecule apart, we performed the co-adsorption of the two molecules on the Si(100) surface to study molecular pairs. Various pairs of molecules have been studied. On one of them, we were able to activate an inter-molecular excitation transfer process by locally exciting one molecule and observing a conformation change of the second molecule of the pair. This result thus shows the electronic control of a bi-molecular device getting rid of substrate mediated electronic process. Finally, as a perspective, this thesis presents a novel technique allowing the controlled local hydrogenation of the Si(100) surface. This is achieved thanks to the passivation of the STM tip by molecular hydrogen at 9K. The tunnel electrons are then used to induce the intra-dimer dissociative adsorption of H2 molecules on the Si(100) surface. This technique could be considered for the passivation of Si(100) or to locally modify molecular circuits.PARIS11-SCD-Bib. Ă©lectronique (914719901) / SudocSudocFranceF
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