Role of metal-molecule chemistry and interdiffusion on the electrical properties of an organic interface:: The Al-F16CuPc case

The chemistry and electronic structure of interfaces between Al and copper hexadecafluorophthalocyanine (F16CuPc) are studied via x-ray photoemission spectroscopy, ultraviolet photoemission spectroscopy (UPS), and current-voltage measurements. Electron injection barriers measured by UPS are reported. Analysis of the Al-F16CuPc reaction shows the formation of a phase of three-dimensional (F16CuPc)(3)Al species. The reacted region is extended at the Al-on-F16CuPc interface and narrow at the F16CuPc-on-Al interface. A series of metal/F16CuPc/metal structures is fabricated to study the impact of the interface chemistry and deposition sequence on device performances. It is found that (F16CuPc)(3)Al forms a low conductivity region, which has considerable bearing on the electron current. The interface fabrication sequence, which defines the thickness of the reacted region, therefore has a profound impact on device performance. (C) 2001 American Institute of Physics.