Effect of complexing agent on the properties of spray-deposited Bi2S3 thin films

Bi2S3 thin films are deposited by a spray pyrolysis technique using oxalic acid as a complexing agent. The films are characterized for their structural, optical and electrical properties. The results are compared with the properties of Bi2S3 thin films produced by the same technique without using the complexing agent. The XRD studies reveal that the growth of the film in a particular direction can be obtained just by controlling the quantity of the complexing agent. The resistivity of complexed films is more than that of as-deposited films. Thermoelectric power (TEP) measurement shows that the carrier concentration and mobility decrease with increasing quantity of oxalic acid. Optical absorption study reveals that the band gap energy, irrespective of the quantity of oxalic acid added to the material, is 1.75 eV. (C) 1998 Elsevier Science S.A. All rights reserved.