Synthesis and Characterization of V-Doped β-In₂S₃ Thin Films on FTO Substrates

Abstract

Intermediate band semiconductors have raised interest as materials to both enhance photovoltaics' efficiency and promote photocatalytic activity driven by visible light. The present work shows the synthesis of In 2 S 3 doped with four different ratios of V using ILGAR technique. This nebulize-spray based technique allows the deposition of In 2 (V)S 3 thin layers controlling the layer thickness and providing high reliability on sample preparation. The samples have been characterized by X-ray diffraction, electron microscopy, profilometry, UV-Vis spectroscopy, inductively coupled plasma mass spectrometry, X-ray photoemission spectroscopy, surface photovoltage spectroscopy, time-resolved microwave conductivity, photoelectrochemical measurements and electrochemical impedance spectroscopy. An optimum of 1.4% V content yielded the highest enhancement of both photocurrent density and photoluminescence compared to undoped In 2 S 3. The results suggest that the inclusion of V in the In 2 S 3 at 1.4% yields a high amount of in-gap levels within the crystalline structure that causes a Fermi energy level shift, which also induces the shift of the level of both valence and conduction band.

Laccase-Catalyzed Bioelectrochemical Oxidation of Water Assisted with Visible Light

“…5), suggesting that the main cause that decreases the faradaic yield of the later system for O 2 production is the photocorrosion of the In 2 S 3 . 53 Still, we can note that the amount of charge transferred in the experiment of Fig. 5A, considering the amount of In 2 S 3 on the electrode active area (∼20 µg) and the specific surface of the material (≈40 m 2 /g), is equivalent to ≈2.0 holes/nm 2 part of which might be accumulated on the surface by a capacitance effect, not by a redox process; the extent of sulphide photocorrosion in these experiments must be therefore limited.…”

“…The use of intermediate-band semiconductors may also improve the fraction of the solar energy spectrum able to drive the photo-induced chemical change, allowing low-energy photons to add their energy and pump electrons to the conductive band. 53,63…”

“…51,52 A photochemical study has revealed a carrier mobility value for In 2 S 3 that is in the same range as compounds frequently used in photoelectrodes, such as the metal oxides semiconductors Cu 2 O, WO 3 and BiVO 4 . 53,54 In 2 S 3 has been tested as photoanode in aqueous media, but only rarely without a sacrificial agent [55][56][57] , so that O 2 photogeneration may be feasible. However such works disregarded the photocorrosion or the generation of byproducts like H 2 O 2 , which have been evidenced 58,59 .…”

Surface Chemistry and Nano-/Microstructure Engineering on Photocatalytic In2S3 Nanocrystals

“…NCs with different shapes and sizes, [23][24]27,29 we followed a slight variation of the procedure reported by K. H. Park et al, 30 to obtain In2S3 NCs with a two-dimensional disk-like morphology. The difference between the synthesis procedure reported by K. H. Park et al and ours is that we used an injection step instead of a heating up procedure, since the latter led to a broader size-distribution in our hands ( Figure S1 Surface modification with PTA: The procedure used to replace native organic ligands with PTA was based on previous work by J. Huang et al 31 Briefly, 1 mL of a 10 mg/mL dispersion of In2S3 NCs in hexane was mixed with 1 mL of a MFA solution that contained 20 mL of TFA and 50 mg (0.0173 mmols) of PTA.…”

Enhanced photoelectrochemical activity of Co-doped β-In2S3nanoflakes as photoanodes for water splitting

“…23 The electro and photoactivity of b-In 2 S 3 can be improved by doping with metals like zirconium, 24 cobalt, 25 tin 26,27 and vanadium. 28 The present work explores the introduction of a transition metal, cobalt (Co) into b-In 2 S 3 nanoakes by chemical bath deposition (CBD) at relatively low temperatures. The doping of Co has been conrmed by optical studies.…”