Selective Synthesis of FeS and FeS₂ Nanosheet Films on Iron Substrates as Novel Photocathodes for Tandem Dye-Sensitized Solar Cells

Abstract

FeS and FeS 2 nanosheet films were selectively synthesized on iron substrates through one-step hydrothermal treatment of iron foil and sulfur powder in the presence or absence of hydrazine. The resulting FeS x (x ) 1, 2) nanosheet films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) and used as novel photocathodes in tandem solar cells with dyesensitized TiO 2 nanorod films as the corresponding photoanode. The photovoltaic properties of the tandem dye-sensitized solar cells were carefully studied. We found that the performance of the FeS nanosheet film photocathode was better than that of the FeS 2 one in the tandem dye-sensitized solar cells. In the case of the FeS nanosheet film photocathode, a short circuit photocurrent (I sc ) of 2.53 mA/cm 2 , an open circuit photovoltage (V oc ) of 0.60 V, a fill factor (FF) of 0.31, and conversion efficiency (η) of 1.32% were obtained under an illumination of 100 mW/cm 2 . This study suggests that these iron sulfide nanosheet films are attractive photocathodes for tandem dye-sensitized solar cells.

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

“…Hu et al 36 and Wang et al 33 only used one S chemical, i.e. elemental sulphur, during the hydrothermal process and their results appear more interesting than those employed two S sources.…”

“…elemental sulphur, during the hydrothermal process and their results appear more interesting than those employed two S sources. For instance, Hu et al 36 synthesized FeS 2 nanosheet lms on iron substrates through a one-step hydrothermal treatment of iron foil and sulphur powder. Fig.…”

Solar Energy Materials

“…The differences between n-type and p-type photocathodes can be illustrated using the examples of pyrite (FeS 2 ) and pyrrhotite (FeS) reported [290] by permission of the PCCP Owner Societies by Hu et al [297] FeS 2 has a band gap suitable for absorption of solar light (E g ¼ 0.95 eV) and a high absorption coefficient (5 Â 10 5 cm -1 at 700 nm), two orders of magnitude bigger than crystalline silicon. FeS has interesting electrical and magnetic properties.…”

“…Reprinted with permission from Hu et al, 2008[297] . Copyright (2008) American Chemical Society made.…”

The search for efficient electrocatalysts as counter electrode materials for dye-sensitized solar cells: mechanistic study, material screening and experimental validation

“…Unfortunately, this material has not been widely studied in the past because of its pyrophoric and non-stoichiometric nature. Hu et al 94 synthesized an FeS nanosheet film on an iron foil using a simple hydrothermal treatment in the presence of sulfur powder. The resulting film was fitted as a CE in tandem-type DSCs using I À =I À 3 as a redox couple, and a PCE of 1.32% was obtained.…”