Highly conducting transparent nanocrystalline Cd1-xSnxS thin film synthesized by RF magnetron sputtering and studies on its optical, electrical and field emission properties

Transparent conducting Cd1-xSnxS thin films have been synthesized by radio frequency magnetron sputtering technique on glass and Si substrates for various tin concentrations in the films. X-ray diffraction studies showed broadening of peaks due to smaller crystal size of the Cd1-xSnxS films, and SEM micrographs showed fine particles with average size of 100nm. Sn concentration in the films was varied from 0% to 12.6% as determined from energy-dispersive X-ray analysis. The room-temperature electrical conductivity was found to vary from 8.086 to 939.7 S cm(-1) and corresponding activation energy varied from 0.226 to 0.076 eV. The optimum Sn concentration for obtaining maximum conductivity was found to be similar to 9.3%. The corresponding electrical conductivity was found to be similar to 939.7 S cm(-1), and the mobility similar to 49.7 cm(2) V-1 s(-1). Hall measurement showed very high carrier concentrations in the films lying in the range of 8.0218 x 10(18)-1.7225 x 10(20) cm(-3). The conducting Cd1-xSnxS thin films also showed good field emission properties with a turn on field 4.74-7.86 V mu m(-1) with variation of electrode distance 60-100 mu m. UV-Vis-NIR spectrophotometric studies of the films showed not needed the optical band gap energy increased from 2.62 to 2.80eV with increase of Sn concentration in the range 0-12.6%. The optical band gap was Burstein-Moss shifted, and the corresponding carrier concentration obtained from the shift also well matched with that obtained from Hall measurement. (c) 2006 Elsevier B.V. All rights reserved.