The Research On The Properties Of FeS₂ Thin Films Prepared By Two Steps

FeS₂ has been considered as a valuable thin film solar cells material since it consists of nontoxic and abundant elements, and it has suitable band gap of about 0.95eV and very high light absorption coefficient (α≥5×10⁵cm^-1,λ≤700nm). The FeS₂ thin films were prepared by two steps at different temperature and time of sulfuration. The effect of technique parameters on the preparation of FeS₂ thin films was discussed by analyzing the structure and the properties of the films. The optimum technique parameters have been obtained: the sulfuration temperature being at 653K and sulfuration time being 6 hours. And FeS₂ thin films with good optical and electrical characteristics have been prepared. When the sulfuration temperature increases from 553K to 653K, the S/Fe ratio of the films increases and the crystallization of the thin films is improved; at the same time, their resistivity increases. When the sulfuration temperature is higher than 653K, some minute cracks occur on the surfaces of the films because of too high temperature and the cracks result in further increase of resistivity and S/Fe ratio. With the increasing of the sulfuration time, the crystallization of the thin films is improved. The intensity of the typical XRD peaks and resistivity of the films are increased. Both the resistivity and the band gap of the thin films decreases a little if the time is longer than 12 h. A suitable method of preparing FeS₂ films has been shown in this work, and it will be a good basis for further research on manufacturing solar cells of FeS₂ thin films.