Strong and singular electronic interaction between naphthalene tetracarboxylic dianhydride (NTCDA) and indium was investigated using various spectroscopic and electric techniques. Doping indium into NTCDA by codeposition caused remarkable changes in the electronic absorption and electron spin resonance spectra, which were attributed to a partial charge transfer from the metal to the carbonyl oxygen. X-ray diffraction and infrared absorption measurements revealed that these electronic interactions prevent aggregation of the organic molecules, resulting in formation of microscopically mixed and amorphous-like films. In addition, indium doped NTCDA showed very high conductivity exceeding 10−2 S/cm, and some stability in under atmospheric condition.
Ken-ichi Nakayama, Yasuro Niguma, Yoshitaka Matsui, Ryoji Miyamoto, Masaaki Yokoyama, "Electronic Interaction and Electric Property in Vacuum Codeposited Films of Naphthalene Tetracarboxylic Derivatives and Metals" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP20), 2004, pp 524 - 527, https://doi.org/10.2352/ISSN.2169-4451.2004.20.1.art00003_2