Pyrite Nanocrystal Solar Cells: Promising, or Fool’s Gold?

Abstract

Pyrite-phase iron sulfide (FeS2) nanocrystals were synthesized to form solvent-based dispersions, or "solar paint," to fabricate photovoltaic devices (PVs). Nanocrystals were sprayed onto substrates as absorber layers in devices with several different architectures, including Schottky barrier, heterojunction, and organic/inorganic hybrid architectures, to explore their viability as a PV material. None of the devices exhibited PV response. XRD and Raman spectroscopy confirmed the pyrite composition and phase purity of the nanocrystals. The electrical conductivity of the nanocrystal films was about 4 to 5 S/cm, more typical of metal nanocrystal films than semiconductor nanocrystal films, and the lack of PV response appears to derive from the highly conductive surface-related defects in pyrite that have been proposed.

Microwave-hydrothermal synthesis of Co-doped FeS2 as a visible-light photocatalyst

“…While the peak at 426 cm -1 originated from Fe-S mixed vibrational modes. These peaks were consistent with the literature [26]. In addition, no other Raman peaks belonging to CoS 2 and CoS [27] were observed, which demonstrated the pure phase of the Co 2?…”

Scientific and Technological Assessment of Iron Pyrite for Use in Solar Devices

“…Hence, iron pyrite NCs were chosen for this investigation. Steinhagen et al, [62] working with different configurations such as Schottky barrier cell and heterojunction solar cell, demonstrated that the solar-cell performanceo f iron pyrite nanocrystals was poor and their rectification ratio was limited by the large leakage current. However, they did not employa ny sulfurization heat treatment on the particles but used al igand exchange process to removet he organic surface ligands.A si ron pyrite is inherently ag ood photon absorber, the electron-a nd hole-extraction strategies must be improved to prepare better photodiodesthat could exhibit higher rectificationr atios.W ed eployed n-type (ZnO)a nd ptype (CuI) layers to extract electrons and holes more effi- III /Co II electrolyte.…”

Hard X-ray photoelectron and X-ray absorption spectroscopy characterization of oxidized surfaces of iron sulfides

“…These minerals are frequently found together with non-ferrous base metals and precious metals in ores and play an important role in the biogeochemical sulfur cycle and other environmental processes [1][2][3][4]. Pyrite (FeS 2 ) has a cubic crystal lattice composed of low-spin ferrous iron and disulfide S 2 2− groups with a bulk band gap of about 0.95 eV [5][6][7]; it is one of the promising materials for photovoltaic [8,9], battery cathode [10,11], thermoelectric [12] and other applications. Pyrrhotites (Fe 1−x S, 0 < x < 0.2) crystallize in a NiAs-like structure consisting of highspin Fe 2+ , monosulfide anions and a system of ordered cationic vacancies, having a very narrow gap of about 0.05 eV [1,13,14].…”