TCNQ Grown on Cu (001): Its Atomic and Electronic Structure Determination

10 pags., 7 figs.In this paper we have resolved by means of “in situ” X-ray diffraction studies the atomic structure of the TCNQ films from 0.4 to 17 ML thickness grown on Cu(001) substrate. The film grown at low temperature, is a well crystallized and well oriented single phase. The TCNQ film has a (020) orientation. The electronic properties of the film have been studied by means of XPS and UPS spectroscopies. The measured electronic density has been compared to the theoretical ab-inito calculations. In this paper we have studied the structural and electronic properties of relatively thick films of TCNQ on Cu(100). Our results demonstrate that the strong charge transfer between the metallic substrate and the first layer of TCNQ molecules have important consequences for the film electronic and structural properties of films even as thick as 17 ML. From the structural point of view, the films grow with a well-defined (020) orientation that matches the modified molecular structure of the first layer. This first monolayer structure was previously explained in literature in terms of adsorbate-induced reconstruction of the Cu surface. From the electronic point of view, charge transfer leads to band bending and determines that barrier for electron injection across the metal/organic interface. © 2016 American Chemical SocietyThis work was supported by the Spanish CICyT under Grant No. MAT2013-47869-C4-3-P. J.I.B. would like to thank the Abengoa Research Center under “The Virtual Material Design Project” (2nd stage) for his financial support. Parts of this research were carried out at the light source MAX-lab IV and Hasylab at DESY, a member of the Helmholtz Association (HGF).Peer Reviewe