EFFECT OF IN ADDITIONS ON THE ELECTRICAL-PROPERTIES OF SN0.8GE(0.2)TETHIN-FILMS OBTAINED BY LASER SPUTTERING

The electrical conductivity, Hall coefficient, and Seebeck coefficient in thin films of solid solutions of (Sn0.8Ge0.2)(1-x)In-x Te (x = 0-0 .2) have been studied in the temperature 77-400 K. Films 200-1200 Angs trom thick were obtained by laser sputter-coating on mica substrates. These films have a Hall concentration of holes p = 2 x 10(20)-3 x 10(2 1) cm(-3), a mobility R sigma = 1 - 30 cm(2)/(V . sec), and a conducti vity in the range rho = 2.5 x 10(-4)-3 x 10(-3) Omega . cm. All these parameters are weakly dependent on temperature. A characteristic minim um close to p similar or equal to 7 x 10(20) cm(-3) is detected on the isotherms of the dependence of the Seebeck coefficient on the hole co ncentration, indicating that the valence band of the solid solution ha s a complex structure. (C) 1996 American Institute of Physics.