Sb-doping effects on optical and electrical parameters of SnO2 films

Undoped and Sb-doped SnO2 films similar to 100 nm thick have been deposited by electron beam evaporation from bulk samples prepared using sintering technique. Either undoped or Sb-doped SnO2 films are nearly amorphous, resistive and transparent. With increasing Sb content, the resistivity slightly decreases and then increases with further addition of Sb. which acts as donor and/or acceptor impurity atom in the SnO2 lattice, respectively. Besides, the doping of Sb inside the SnO2 lattice was associated with the increase in the film transmission at solar maximum wavelength and the width of optical band gap; which were interpreted in terms of the interaction between the two oxidation states of antimony, Sb3+ and Sb5+ and the increase of atomic bond energy, respectively. Moreover, the addition of Sb to the SnO2 lattice has proved to affect significantly on the refractive index, the extinction coefficient, concentration of free carriers, dielectric constant, electric carrier susceptibility and Mott's parameters, which have been explained and correlated to the film microstructure change. (C) 1999 Elsevier Science Ltd. All rights reserved.