Local area characterization of organic ultra-thin films by scanning tunneling spectroscopy

In this study, we measured the scanning tunneling spectroscopy (STS) of copper phthalocyanine (CuPc) thin films deposited on substrates or STM tips of silicon (p- and n/sup +/-Si) and metal (Pt-Ir, Al). The STS measurements using semiconductor tip and organic film coated tip are powerful to investigate the surface and interface analysis of organic thin films. The results obtained here explain the asymmetry of the STS characteristics and provide important information such as band gap and local density of states of organic thin films. These basic characterization using STS will help to clear understanding with molecular level and future device applications.