Phase-pure iron pyrite nanocrystals for low-cost photodetectors

Abstract

Earth-abundant iron pyrite (FeS2) shows great potential as a light absorber for solar cells and photodetectors due to their high absorption coefficient (>105 cm-1). In this paper, high-quality phase-pure and single crystalline pyrite nanocrystals were synthesized via facile, low-cost, and environment friendly hydrothermal method. The molar ratio of sulphur to iron and the reaction time play a crucial role in determining the quality and morphology of FeS2 nanocrystals. X-ray diffraction and high-resolution transmission electron microscopy confirm that phase-pure and single crystalline pyrite nanocrystals can be synthesized with high sulphur to iron molar ratio and sufficient reaction time. For the first time, a crystalline nanogap pyrite photodetector with promising photocurrent and UV-visible photoresponse has been fabricated. This work further demonstrates a facile route to synthesize high-quality FeS2 nanomaterials and their potential in optoelectronic applications.

Uranium sorption characteristics onto synthesized pyrite

“…It is almost consistent with iron to sulfur abundance ratio of 1:2. Results show that the as-synthesized sample has the same peak height ratio as in pure pyrite (not shown) reported previously [18]. The EDS measurement shows a high peak of uranium in uranium-sorbed pyrite at 2.2 keV, which confirms that U(VI) was sorbed on pyrite.…”

Understanding the Surfaces and Crystal Growth of Pyrite FeS2

“…Pyrite growth, whether on the geological scale or synthesized in the laboratory, depends on external conditions. Under the conditions of low [S] / [Fe] ratio (low sulfur content, high iron content), {001} facets grow first and in the opposite case of sulfur-rich environment, the {210} and {111} facets are favored 29,[31][32][33] . The effect of the sulfur content can be evaluated theoretically using the chemical potential method.…”

Morphology controllable syntheses of micro- and nano-iron pyrite mono- and poly-crystals: a review

“…Although various types of surfactants have been supplied in synthesis of pyrite, 27,30,31,33,34,37,38,42,43,45 only a few obtained the {100} and/or {111} facets. 33,34 No facets have been synthesized by employing CTAB and all the pyrite crystals synthesized with CTAB tend to form aggregations.…”