Study of 4the influence of annealing parameters on the optical and compositional properties of ZnS, ZnS:Mn and ZnS:Sm grown by Sol Gel

Abstract

Samples with 3 layers of ZnS were prepared on glass substrate by the Sol Gel method. The annealing parameters were varied as follows: each of the 3 constituent layers of sample 1 was annealed at 400 °C for 12 hrs. For sample 2, the 1rst and 2nd layers were annealed at 300 °C for 2hrs each and the 3rd one at 400 °C for 12 hrs. For sample 3, the 1rst and 2nd layers were annealed at 200 °C for 2hrs each and the 3rd at 400 °C for 12 hrs. Furthermore, 2 samples: one with 3 layers of ZnS:Mn and the other with 3 layers of ZnS:Sm were prepared and annealed similarly to sample 2. AES depth profiles show a transversal diffusion of S in sample 1, a sulfur deficiency in sample 2, and a non distributed excess of S in sample 3. The absorption spectra of the 3 ZnS samples are very similar but the absorption edges shift to smaller energy values for the Mn and Sm doped ZnS samples. Sample 1 presents a PL spectrum with 2 bands at 441 and 537 nm while sample 2 presents a similar spectrum but the bands are 16 and 11 nm blue shifted.