Electron depletion and accumulation regions in n-type copper- hexadecafluoro-phthalocyanine and their effects on electronic properties

We investigated interfacial electronic structures of organic/inorganic heterojunctions formed between copper-hexadecafluoro-phthalocyanine (F ₁₆CuPc) and molybdenum trioxide or lead monoxide by ultraviolet and x-ray photoemission spectroscopies. Obvious energy level bending in F ₁₆CuPc shows the formation of electron depletion and accumulation regions in its contact with molybdenum and lead oxides, respectively. Effects of these depletion/accumulation zones were studied via electronic characteristics of field-effect transistors constructed with these heterojunctions as active layers. Finally, a summary about the heterojunction including organic semiconductor (n-type and p-type) and metal oxide was given, which demonstrated that organic semiconductors can form various space charge regions like conventional inorganic semiconductors. © 2012 American Institute of Physics.