Figure 6 STM images of CuPc molecules adsorbed on the TiO2(011) surface, panels a) and b) show sample before annealing, two distinct phases are observed, panels c) and d) illustrate sample after 2 hour annealing at 150°C, only phase II is visible, the amount of molecule dislocations, vacancies and defects is decreased after annealing, panels e) and f) show sample after two-hour annealing at 200°C, when completely new phase III is formed with up-right molecules, bias voltage +3.0V, tunnelling current 2pA. High resolution STM maps, shown in Figure 6, give more insight into the molecular structure of the islands in the 2nd layer. Phase II is composed of flat-lying molecules forming a brick-wall structure. The separation between neighboring molecules in the direction equals 1.8nm, that is a double of the surface unit cell dimension. The longitudinal separation between neighboring molecular rows also matches the double of the surface cell dimension (approximately 1.15nm). In a consequence, a c(44) superstructure is formed, that is significantly different from previously observed flat-lying molecular structures on different templates (i. e. on graphite [14, T. G. Gopakumar et al., J. Phys. Chem. B 108, 7839 (2004).], VOPc on Au(111) [15, K. W. Hipps, D. E. Barlow, U. Mazur, J. Phys. Chem. B 104, 2444 (2000).], CuPc on graphite and alkane adlayer [16, A. Yin et al., J. Phys. Chem. B 106, 9044 (2002).], on Cu(111) [17, H. Karacuban, M. Lange, J. Schaffert, O. Weingart, Th. Wagner, R. Möller, Surf. Sci. Lett. 603 (2009) L39], on Au(111) [18-20, M. Takada, H. Tada, Chem. Phys. Lett. 392, 265 (2004). J. Y. Grand et al., Surf. Sci. 366, 403 (1996). K. W. Hipps et al., J. Phys. Chem. 100, 11207 (1996).]). At this point, it is worth to noti... ... middle of paper ... ...f phase III ordered layer (one domain). Presumably, the layer is stabilized by the π-π interaction between neighboring molecules and by the interaction of their hydrogen atoms with the π-plane of the first molecular layer [H. Huang et al., Appl. Phys. Lett. 94, 163304 (2009)., S. Tsuzuki et al., J. Am. Chem. Soc. 122, 3746 (2000).]. With regards to possible future applications of the presented system in solar power converting devices or optoelectronics, it is worth to point out here that 200°C annealing not only leads to a reorientation of molecules into the up-right configuration, but also provides large, stable and well-ordered domains with much lower density of defects, molecule dislocations and vacancies when compared to phases I and II. Formation of such large, well-ordered domains is of great importance to increase the efficiency of any optoelectronic device.