Pyrite (FeS2) thin films prepared by spray method using FeSO4 and (NH4)(2)S-x

摘要

A simple spray method for the preparation of pyrite (FeS2) thin films has been studied using FeSO4 and (NH4)(2)S-x as precursors for Fe and S, respectively. Aqueous solutions of these precursors are sprayed alternately onto a substrate heated up to 120degreesC. 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 500degreesC for 30 min. All pyrite films prepared show p-type conduction. They have a carrier concentration (p) in the range 10(16)-10(20) cm(-3) and a Hall mobility (mu(H)) in the range 200-1 cm(2)/ Vs. The best electrical properties (p = 7 x 10(16) cm(-3), mu(H) = 210cm(2)/Vs) 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. (C) 2002 Elsevier Science B.V. All rights reserved. References: 11