Growth of Cu phthalocyanine thin films on Sb passivated vicinal Si(111) with molecular columns parallel to the surface

This study shows a growth of copper phthalocyanine (CuPc) thin films with one-dimensional structures parallel to the surface on Sb-passivated stepped silicon surfaces with (111) orientation. Sb passivation maintains all the step and terrace features on the vicinal Si(111) surface, where subsequently a CuPc sub-monolayer is deposited. The CuPc forms islands of sub-micrometer extension, which shows substantial molecular diffusion on the surface after deposition. In a single island of CuPc, one-dimensional columns of stacked CuPc molecules grow parallel to the step edges of the vicinal Sb-Si(111) surface, which illustrates the strong anisotropy of molecular growth induced by the stepped surface. The self-assembly behavior of CuPc indicates that the Sb passivated surface allows high molecular mobility of CuPc, having anisotropy effect from the stepped substrate structure.