巴黎大学-七大  Prof. Jean Christophe Lacroix 课题组（ITODYS实验室）  招收2020年CSC公派留学生

要求： 化学或者物理化学背景，2019年7月份已取得硕士学位，有托福或雅思成绩，CSC（公派）项目留学生。课题主要方向是分子电子学，仪器涉及扫描隧道显微镜（STM），原子力显微镜（AFM），如有意向望尽快邮件导师Pr. Jean Christophe Lacroix和Dr. Xiaonan Sun。本人是课题组博士生，我的导师认真负责，关心留学生，不论在科研还是生活都给了大家很多帮助。并且该课题在组里进展良好，文章质量和数量一直不错，所以对想出国读博的同学是很好的机会，真心推荐给大家。


研究计划如下，更详细的可以邮件导师。

Type de financement demandé : 4 ans de thèse
Equipe d’accueil : équipe nanoelectrochimie –ITODYS, UMR 7086, Université Paris Diderot(Paris 7)
Pôle : Sciences Exactes et Technologie / Exact Sciences and Technology
Ecole doctorale : ED 388 - Chimie Physique et Chimie Analytique de Paris-Centre
Langue de Travail : Anglais
Encadrants : Pr. Jean Christophe Lacroix/Dr. Xiaonan Sun
Contact emails : Lacroix@uinv-paris-diderot.fr or  Sun.Xiaonan@univ-paris-diderot.fr

The use of single molecules in molecular electronics aims to miniaturize the electronic devices in size and to optimize the electronics in efficiency. The engineer of single molecules on surface, the formation and the conductance measurement of molecular junctions controlled with a single or few molecules are of great interest and are the focus of this PHD proposal. Few important scientific questions will be addressed 1) how to expand on surface reactions 2) to how to stabilize single molecule molecular junctions, 3) can we consider that a molecular junction involving 10 molecules has a conductance ten time that of a molecular junction involving a single molecule. In this respect, the proposed PHD project will mainly focus on the following points:

Part I: Engineering and visualization of on surface reaction a sub-molecular level by STM  
Molecules bearing pyridine groups linked by bridges with different functionalities can self-assembly at the solid-liquid interface and form ordered supramolecular self-organizations as depicted in Figure 1. By introducing metal ions, an on surface reaction is triggered where coordinate polymers are successfully formed. [1-3]  This reaction will be further investigated by changing the metal type and changing the different functionalities of the bridges.  Scanning tunneling microscopy (STM) will be employed to directly visualize or to engineer the on surface reaction. The surface properties and their functionality, with different metal coordination, 2D chirality and photochromic sensitivities, will be studied and be interpreted accordingly


Part II: Generating stable Single molecular junction studied by STM-BJ
Functional molecules (investigated in Part I) with active anchoring groups are selected in investigating the single molecular junctions. STM-based break junction (BJ) measurements will be performed where STM tip will be controlled to crash on molecule decorated the surface and to pull-out or where it is used to contact a molecule already attached to an electrode in a perpendicular configuration. The generated metal-molecule-metal junctions will be studied Conductance-vs-extension (I(z)) curves will be extracted while pulling-out the junctions (see Figure .2. [4-6]) or conductances-vs-time curves will be obtained and will allow the measurements of the conductance of a single molecule bearing the various functionalities studied in part one, The PHD  project will be to study single molecular conductance with improved stability using functionalizing the STM tips and to comprehend the charge transport properties.

Part III: Molecular junction Involving between 10 and 1000 molecules studied by C-AFM
The formation and the conductance measurement of molecular junctions controlled by a few molecules are as well of great interest in studying their electronic and mechanical properties in comparison with the single molecular junction. Functional molecules which have been studied in Part II will be deposited on nano lithographic patterned samples. Groups of molecules will be selectively absorbed on the active nano patterns. Conductive atomic force microscopy (C-AFM) will be employed to probe the conduction. The C-AFM tip and the nano patterns will behave as two electrodes so that the current-voltage (I-V) characterization of the molecules between the two electrodes will be recorded directly. [7-10]



[1] Nguyen V. Q.; Sun, X.; Lafolet, F. ; Audibert, F. F. ; Miomandre F. ; Lemercier, G. ; Loiseau, F. ; Lacroix, J. C. ; JACS (2016) 138, 9381-9384.
[2] Sun X, Yao X, Lafolet F, Lemercier G, Lacroix JC,  JPCL (2019) 10, 4164-4169.
[3] Hnid I, Sun X, Frath D , Lafolet F and Lacroix JC,  Nanoscale (2019) just accepted
[4] Xu B. and Tao N. J., Science (2003) 301, 1221-1223,
[5 ] Janin M.; Ghilane; J.;  Lacroix J. C., JACS (2013) 135, 6, 2108-2111.
[6] Bayat, A.; Lacroix J. C.; McCreery, R. L.; JACS (2016) 138, 12287-12296
[7] Q. V. Nguyen, P. Martin, D. Frath, M.L. Della Rocca, F. Lafolet, S. Bellinck, P. Lafarge, J.C. Lacroix
JACS (2018) 140,10131-10134.
[8] Q. V. Nguyen, P. Martin, D. Frath, M. L. Della Rocca, F. Lafolet, C. Barraud, P. Lafarge, V. Mukundan, D. James, R.L McCreery, J. C. Lacroix, JACS (2017) 139 , 11913-11922.
[9] U. M. Tefashe, Q. V. Nguyen, F. Lafolet, J. C. Lacroix, R. L. McCreery, JACS (2017) 139,7436-7439.
[10] D. Frath, V. Q. Nguyen, F. Lafolet, P. Martin, J. C. Lacroix, ChemCommu (2017) 53, 10997-11000. 返回小木虫查看更多