Lin, Meng-KaiNakayama, YasuoZhuang, Ying-JieSu, Kai-JunWang, Chin-YungPi, Tun-WenMetz, SebastianPapadopoulos, Theodoros A.Chiang, Tai-ChangIshii, HisaoTang, Shu-Jung2017-03-022017-03-022017-02-17Lin, M.-K., et al. (2017). Control of the dipole layer of polar organic molecules adsorbed on metal surfaces via different charge-transfer channels. Physical Review B, 95(8), 085425. DOI: 10.1103/PhysRevB.95.08542510.1103/PhysRevB.95.085425http://hdl.handle.net/10034/620425Organic molecules with a permanent electric dipole moment have been widely used as a template for further growth of molecular layers in device structures. Key properties of the resulting organic films such as energy level alignment (ELA), work function, and injection/collection barrier are linked to the magnitude and direction of the dipole moment at the interface. Using angle-resolved photoemission spectroscopy (ARPES), we have systematically investigated the coverage-dependent work function and spectral line shapes of occupied molecular energy states (MES) of chloroaluminium-phthalocyanine (ClAlPc) grown on Ag(111). We demonstrate that the dipole orientation of the first ClAlPc layer can be controlled by adjusting the deposition rate and post annealing conditions; the ELA at the interface differs by ~0.4 eV between the Cl-up and -down configurations of the adsorbed ClAlPc molecules. These observations are rationalized by density-functional-theory (DFT) calculations based on a realistic model of the ClAlPc/Ag(111) interface, which reveal that the different orientations of the ClAlPc dipole layer lead to different charge-transfer channels between the adsorbed ClAlPc and Ag(111) substrate. Our findings provide a useful framework towards method development for ELA tuning.enhttp://creativecommons.org/licenses/by-nc-nd/4.0/Metal-organic interfaceAg(111)/ClAlPcArticle2469-9969Physical Review B