Chemical vapour transport of pyrite (FeS2) with halogen (Cl, Br, I)

Vapor growth and characterization of pyrite (FeS2) doped with Co, Ni, and As: Variations in semiconducting properties

“…The tubes were positioned in a horizontal tube furnace with a temperature gradient of approximately 700 to 600 1C over 18 cm for 14-21 days, with the charge in the hot end of the tube. The transport process, described by Fiechter et al [5], results in macroscopic pyrite crystals with crystal faces up to 8 mm grown in the cool end of the tubes. Excess FeS constrains the S fugacity and prevents excess S vapor from inhibiting the transport process.…”

“…Large crystals of pyrite were grown with chemical vapor transport (CVT) using 99% pure anhydrous FeBr 3 purchased from Strem Chemicals as the transport agent [5,8,18,21] in an Fe 1Àx S/FeS 2Ày buffered system. Approximately one gram of an FeS-S mixture in a molar ratio of approximately 5:4 was placed in an evacuated quartz ampoule (inner diameter 7 mm, average length 18 cm) with approximately 0.3 g FeBr 3 .…”

“…It occurs with most metal sulfide ores as well as with coal. Due to its semiconducting properties and its photo-potential, pyrite has attracted attention as a nontoxic, inexpensive material for photovoltaic applications in the form of thin films [2][3][4][5][6][7][8][9], though it is susceptible to oxidative degradation [1,10]. Pyrite oxidation has been extensively studied, both for its role in the separation of pyrite from other valuable sulfide minerals and gold, and for its role in the degradation of the environment through acidification of surface and ground water, often referred to as acid mine drainage.…”

First-principles studies of the electronic properties of native and substitutional anionic defects in bulk iron pyrite

“…However, their transport properties such as carrier concentration, Hall mobility and resistivity exhibit large variations depending on the fabrication methods. 20,21,22,23,24,25,26,27 On the other hand, although p-type doping with P or As has been reported, the source of hole carriers is ambiguous due to the weak dependence of transport properties on the concentration of impurities, rather small Hall voltage, and large uncertainty caused by poor contacts. 21,22,24 A clear understanding of the key factors that govern the transport properties of pyrite is indispensable for solar energy conversion applications.…”

The Renaissance of Iron Pyrite Photovoltaics: Progress, Challenges, and Perspectives

“…Studies were focused on creating thin films by first chemical vapor transportation (CVT) and then follow-up studies were done using metal organic chemical vapor deposition (MOCVD) [37][38][39][40][41]. It was found that they could produce pure pyrite films by adjusting pressure, temperature, and molar concentrations of the reactants.…”