Structural Characterization of CdSe-doped Sol-gel Silicophosphate Films

Abstract

UDC 544.774.2

SiO₂-P₂O₅ films doped with CdSe have been prepared and investigated for temperature sensors applications. The films have been synthesized by sol-gel method, spin coating technique, the deposition being made on glass substrates. The sols have been prepared from tetraethylorthosilicate (TEOS) and phosphoric acid as precursors for SiO₂ and P₂O₅, respectively, together with ethanol and water as reaction environment and a hydrolysis reagent, respectively. The films have been deposited at three rotation rates: 1000 rpm, 2000 rpm and 3000 rpm, starting on the first day after the sol preparation moment and going on, four days consecutively, and then on the eighth day. We have analyzed the influence of the rotation rate and the time elapsed since the sol preparation till the deposition moment on the structural properties of the doped films. The films deposited at each rotation rate have been annealed at 200^oC, 300^oC, 350^oC, 400^oC, and 550^oC in order to investigate the structural modifications noticed during the formation process of silicophosphate network. 

Keywords: FTIR spectroscopy, Raman spectroscopy, sol-gel method, CdSe.