C-60 uniformly doped and delta-doped GaAs layers are grown by migration enhanced epitaxy method Crystalline and electrical characteristics of the layers are investigated by reflection high energy electron diffraction, X-ray diffraction and capacitance-voltage (C-V) measurements. C-60 high-concentration doping is found to introduce 2D defects, and X-ray diffraction pole-figure measurements show that the rotational domains appear predominantly on {1 1 1}A plane. This indicates that C-60 molecules are mainly incorporated on the dangling bonds of Ga atoms due to the high binding energy between C-60 molecules and Ga atoms. C-60 uniformly doped GaAs layers show highly resistive characteristics, suggesting that C-60 molecules cannot be decomposed into isolated C atoms in the GaAs lattice, and they behave as if they were electron traps or strong recombination centers. C-V profiles of Cr-Au/C-60 delta-doped GaAs Schottky diode suggest that C-60 molecules in GaAs lattice produce electron traps which can be charged or discharged by applied electrical field. (c) 2008 Elsevier B.V. All rights reserved.