Vacuum annealing temperature on spray In₂S₃ layers

¹ Laboratoire de Physique des Matériaux et des Nanomatériaux appliquée à l’environnement, Université de Gabès, Faculté des Sciences de Gabès, Cité Erriadh Manara Zrig 6072 Gabès, Tunisie
² LPMS, Département de Génie Industriel, Ecole Nationale d’Ingénieurs de Tunis, PB 37, Le Belvédère 1002, Tunisie
³ Faculty of Applied Sciences, Department of Physics, Umm AL-Qura University, Saudi Arabia, KSA

^a e-mail: timoumiabdelmajid@yahoo.fr

Received: 23 July 2013
Revised: 7 December 2013
Accepted: 6 January 2014
Published online: 14 February 2014

Abstract

Indium sulfide In₂S₃ thick films are deposited on glass substrates using spray technique over the optimum conditions experiments (T_s = 340 °C, S/In = 2). The films are polycrystalline and have thickness of about 1.8 μm. These films are annealed in a vacuum sealed pyrex tubes (10⁻⁵ torr). Physico-chemical characterizations by SEM observation, X-ray diffraction and EDX analysis are undertaked on these films. This treatment has improved crystallinity of samples. It has allowed thus to stabilize β and γ varieties of In₂S₃ material. In₂O₃ and In₆S₇ phases have appeared with very weak intensities at high temperatures. The best structure quality are obtained at 300 °C for the optimum annealed temperature (T_s = 340 °C, S/In = 2), for which samples are constituted in dominance by γ phase oriented preferentially towards (1 0 2). The grain size is 42 nm of this phase. Chemical composition of such films has changed relatively to non-treated film but it seems not be affected by treatment temperature. Atomic molar ratio S/In is obtained for 0.9. Optical study shows that these layers are transparent in the visible and optical direct band gap increases as function of annealed temperature.