Influence of S/Mn molar ratio on the morphology and optical property of γ-MnS thin films prepared by microwave hydrothermal

• Published in: Journal of alloys and compounds 2013-02, Vol.549, p.1-5
• Main Authors: Yu, Xin, Li-yun, Cao, Jian-feng, Huang, Jia, Liu, Jie, Fei, Chun-yan, Yao
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Crystallization; Exact sciences and technology; Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids); Manganese; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Microwave hydrothermal method; Microwaves; Morphology; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Orientation; Physics; Thin films; X-rays; γ-MnS
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2012.09.032

► The influence of the precursor solution molar ratio of S/Mn. ► The degree of orientation of the γ-MnS film decrease slightly with increasing the S/Mn from 2.0 to 4.0. ► Film quality is strongly affected by the initial nucleation. ► The absorption edge obviously shifts to a higher wavelength with the increase of the S/Mn molar ratio from 2.0 to 4.0. Well crystallized γ-MnS thin films were successfully synthesized at low temperature and short processing time via a novel microwave hydrothermal (M-H) process without any complexing agent by using manganese chloride and thioacetamide as source materials. The influence of different S/Mn molar ratio in the precursor solution on the phase compositions, morphologies and optical properties of the as-deposited films was investigated. The as-deposited γ-MnS thin films were characterized by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and ultraviolet–visible (UV–vis). Results show that the wurtzite phase γ-MnS thin films with good crystallization can be achieved when S/Mn molar ratio is controlled at 2.0–4.0. The deposited γ-MnS thin films exhibit (100) orientation growth with the thickness of 300–500nm. With the increase of S/Mn molar ratio from 2.0 to 4.0, the orientation growth is weakened while the dense and uniform of the as-deposited γ-MnS thin films are obviously improved and the corresponding band gap of the thin films increase from 3.88 to 3.97eV.