Photoelectrochemical properties of indium doped iron oxide

Towards highly efficient photoanodes: boosting sunlight-driven semiconductor nanomaterials for water oxidation

“…In addition to nonisovalent substitutional doping, isovalent substitutional doping, such as Al 3+ , In 3+ , and Cr 3+ doping, have also been investigated, 61,[79][80][81] including adding small quantities of dopants that could, in principle, form oxides that are isostructural with hematite, thereby directing the crystallinity of the hematite photoelectrode. 61 Unlike nonisovalent substitutional doping that creates excess electron-hole pairs in the conduction process, Al 3+ isovalent substitutional doping causes a contraction of the crystal lattice due to the smaller ion radius of Al 3+ compared with Fe 3+ , which benets the small polaron migration and results in improved hematite conductivity and photoresponse.…”

Probing the photoelectrochemical properties of hematite (α-Fe2O3) electrodes using hydrogen peroxide as a hole scavenger

“…2 Polycrystalline thin films were deposited by chemical vapor deposition (CVD) 3 and reactive sputtering, achieving an IPCE of 21% at 400 nm and 1.46 V RHE . 4,5 Many nanostructured porous electrodes were also investigated. These include electrodes fabricated by sintering colloidal hematite nanoparticles that achieved an IPCE of 20% at 400 nm and 1.43 V RHE .…”

Nanostructuredα-Fe2O3 in PEC Generation of Hydrogen

“…This type of coating of oxides on a-Fe 2 O 3 can be used to achieve stable and efficient photoelectrodes in PEC cell cells, as the front surface of the photoelectrode can be protected from photocorrosion by depositing a thick layer of stable electrocatalyst and illuminating the back surface, kept unexposed to the solution. Reactively sputtered indium-doped iron-oxide films of 25 nm thickness prepared by Schumacher et al displayed double the quantum yield for the back face than for the front face [54]. A decrease in the ratio of effective quantum efficiencies between the back face and front face was observed over the wavelength range 420-600 nm, which was attributed to absorption by the ITO.…”

“…Schumacher et al investigated reactively sputtered and plasma-oxidized iron-oxide films and the effect of thermal treatment, vacuum annealing and indium incorporation on their surface composition, and photoelectrochemical, impedance and spectroscopic properties [54]. Auger depth-profile data showed no detectable amount of indium incorporation in the plasmaoxidized films, while the reactively sputtered films contained 20 at% indium at the front surface, decreasing to 8% in the bulk, and then increasing towards the indium tin oxide (ITO) interface.…”

“…Al(III)-and Cr(III)-doping in a-Fe 2 O 3, as observed by Sartoretti, exhibited poor photoresponse [43]. In a study by Schumacher et al, incorporation of indium into 25 nm thick iron-oxide films was shown to produce a small increase in quantum efficiency, while no change in flatband potential and bandgap was obtained [54]. Effects were explained in terms of a localized states model for a-Fe 2 O 3 and it was concluded that most of the impurity is taken up in octahedral lattice sites, substituting for iron.…”