Electrical transport studies in nanocrystalline CdSe/SiO2 composite films

SiO2/CdSe/SiO2 composite films in nanocrystalline form were deposited on qu artz substrates at similar to 20 Pa with deposition temperatures ranging fr om 220 to 240 K using a multi-target magnetron sputtering system. Optical, electrical, and microstructural (TEM and AFM) studies were carried out on t he composite films. Studies of the variation of conductivity with temperatu re indicated Efros hopping within the Coulomb gap to be the predominant car rier transport process in the composite films. Furthermore, a crossover fro m a 'soft' to a 'hard' Coulomb gap was noticed with lowering of temperature . (C) 2001 Elsevier Science B.V. All rights reserved.