Semiconducting behaviour in Bi<inf>60</inf>Sb<inf>40</inf> alloy thin films

Electrical resistance measurements of annealed Bi60 Sb40 alloy thin films of various thicknesses vacuum deposited at different substrate temperatures have been carried out from about 80 K to 500 K. The observed variation in resistance with temperature has been explained on the basis of impurity conduction, band to band transition, grain boundary barrier activation of carriers and metallic behaviour in different regions of temperature. The larger band gap values observed compared to bulk are attributed to the quantum size effect and high dislocation density. The decrease in the grain boundary barrier activation energy with increasing thickness and substrate temperature has been explained on the basis of Slater's model. © 1981 Pergamon Press Ltd/Printed in Great Britain.