SiO2/CdSe/SiO2 composite films in nanocrystalline form were deposited on quartz substrates at similar to 20 Pa with deposition temperatures ranging from 220 to 240 K using a multi-target magnetron sputtering system. Optical, electrical, and microstructural (TEM and AFM) studies were carried out on the composite films. Studies of the variation of conductivity with temperature indicated Efros hopping within the Coulomb gap to be the predominant carrier transport process in the composite films. Furthermore, a crossover from a 'soft' to a 'hard' Coulomb gap was noticed with lowering of temperature.