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Pyrite (FeS2) thin films prepared by spray method using FeSO4 and (NH4)2Sx

2003; Elsevier BV; Volume: 75; Issue: 3-4 Linguagem: Inglês

10.1016/s0927-0248(02)00205-2

1879-3398

Akio Yamamoto, Makoto Nakamura, Arisa Seki, E.L. Li, Akihiro Hashimoto, Shigeyuki Nakamura,

Extraction and Separation Processes

A simple spray method for the preparation of pyrite (FeS2) thin films has been studied using FeSO4 and (NH4)2Sx as precursors for Fe and S, respectively. Aqueous solutions of these precursors are sprayed alternately onto a substrate heated up to 120°C. Although Fe–S compounds including pyrite are formed on the substrate by the spraying, sulfurization of deposited films is needed to convert other phases such as FeS or marcasite into pyrite. A single-phase pyrite film is obtained after the sulfurization in a H2S atmosphere at around 500°C for 30 min. All pyrite films prepared show p-type conduction. They have a carrier concentration (p) in the range 1016–1020 cm−3 and a Hall mobility (μH) in the range 200–1 cm2/V s. The best electrical properties (p=7×1016 cm−3, μH=210 cm2/V s) for a pyrite film prepared here show the excellence of this method. The use of a lower concentration FeSO4 solution is found to enhance grain growth of pyrite crystals and also to improve electrical properties of pyrite films.