Abstract
Tris(O-ethylxanthate)bismuth(iii) (1) and tris(O-ethylxanthate)antimony(iii) (2) were synthesized and used as precursors for the preparation of Bi2-2xSb2xS3 alloys (x = 0, 0.2, 0.4, 0.6, 0.8 and 1) using solventless thermolysis. The p-XRD peaks at all ratios corresponded well to an orthorhombic crystal structure between that of Bi2S3 and Sb2S3. The lattice parameters a and b were found to increase linearly as the Sb content increases in the Bi2-2xSb2xS3 samples, whereas c decreases gradually with increasing Sb. For all samples the elemental composition and uniform stoichiometry was determined by EDX analysis and ICP-OES. Incorporation of Sb into Bi2S3 led to an increase in the band gap from 1.66 eV at x = 0 to 2.19 eV at x = 1. The morphologies of the alloys were investigated using SEM, revealing different texturing as the composition changes from Bi2S3 to Sb2S3.