Semiconductor-like carrier conduction and its field-effect mobility in metal-doped C60 thin films

• Published in: Japanese Journal of Applied Physics Vol. 32; no. 8A; pp. L1070 - L1073
• Main Authors: HOSHIMONO, K, FUJIMORI, S, FUJITA, S
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese journal of applied physics 01.08.1993
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Localized state; Temperature; Electrical conductivity; Semiconductor materials; Doping; Charge carrier mobility; Antimony; N type conductivity; High temperature; Experimental study; Indium; Thin film; Fullerenes; Charge carrier concentration
• ISSN: 0021-4922; 1347-4065

Conductivity and its temperature dependence, conduction type, and field-effect mobility in metal (In or Sb)-doped C60 thin films are investigated together with those of undoped films. All electrical measurements have been conducted without exposure to air after deposition, in order to minimize the degradation of films due to incorporation of oxygen. For films with both dopants, (1) the conductivity is several orders of magnitude higher than that of undoped films, (2) the conductivity follows a semiconductor-like temperature dependence with the activation energy of 0.10-0.17 eV, which is much lower than that of the undoped films, 0.51 eV, (3) the conduction is n-type, and (4) the field-effect mobility is 0.03-0.04 sq cm/V s. Enhancement of conductivity in metal-doped C60 films is attributed to the increase of both carrier concentration and mobility.