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The ternary chalcogenide Cu3VSe4 (CVSe) with sulvanite structure has been theoretically predicted to be a promising candidate for photovoltaic applications due to its suitable band-gap for solar absorption and the relatively earth-abundant elements in its composition. To realize the absorber layer via an inexpensive route, printed thin-films could be fabricated from dispersions of nano-sized Cu3VSe4 precursors. Herein, cubic Cu3VSe4 nanocrystals were successfully synthesized via a hot-injection method. Similar with reported Cu3VS4 nanocrystals, Cu3VSe4 nanocrystals with cubic structure exhibit three absorption bands in the UV-Visible range indicative of a potential intermediate bandgap existence. A thin film fabricated by depositing the nanoparticles Cu3VSe4 on FTO coated glass substrate, exhibited a p-type behavior and a photocurrent of ~ 4 μA/cm2 when measured in an electrochemical cell setting. This first demonstration of photocurrent exhibited by a CVSe nanocrystals thin film signifies a promising potential in photovoltaic applications.
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Cascade synthesis and optoelectronic applications of intermediate bandgap Cu3VSe4 nanosheets
Abstract Two-dimensional (2D) ternary materials recently generated interest in optoelectronics and energy-related applications, alongside their binary counterparts. To date, only a few naturally occurring layered 2D ternary materials have been explored. The plethora of benefits owed to reduced dimensionality prompted exploration of expanding non-layered ternary chalcogenides into the 2D realm. This work presents a templating method that uses 2D transition metal dichalcogenides as initiators to be converted into the corresponding ternary chalcogenide upon addition of copper, via a solution-phase synthesis, conducted in high boiling point solvents. The process starts with preparation of VSe 2 nanosheets, which are next converted into Cu 3 VSe 4 sulvanite nanosheets (NSs) which retain the 2D geometry while presenting an X-ray diffraction pattern identical with the one for the bulk Cu 3 VSe 4 . Both the scanning electron microscopy and transmission microscopy electron microscopy show the presence of quasi-2D morphology. Recent studies of the sulfur-containing sulvanite Cu 3 VS 4 highlight the presence of an intermediate bandgap, associated with enhanced photovoltaic (PV) performance. The Cu 3 VSe 4 nanosheets reported herein exhibit multiple UV–Vis absorption peaks, related to the intermediate bandgaps similar to Cu 3 VS 4 and Cu 3 VSe 4 nanocrystals. To test the potential of Cu 3 VSe 4 NSs as an absorber for solar photovoltaic devices, Cu 3 VSe 4 NSs thin-films deposited on FTO were subjected to photoelectrochemical testing, showing p-type behavior and stable photocurrents of up to ~ 0.036 mA/cm 2 . The photocurrent shows a ninefold increase in comparison to reported performance of Cu 3 VSe 4 nanocrystals. This proves that quasi-2D sulvanite nanosheets are amenable to thin-film deposition and could show superior PV performance in comparison to nanocrystal thin-films. The obtained electrical impedance spectroscopy signal of the Cu 3 VSe 4 NSs-FTO based electrochemical cell fits an equivalent circuit with the circuit elements of solution resistance (R s ), charge-transfer resistance (R ct ), double-layer capacitance (C dl ), and Warburg impedance (W). The estimated charge transfer resistance value of 300 Ω cm 2 obtained from the Nyquist plot provides an insight into the rate of charge transfer on the electrode/electrolyte interface.
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- Award ID(s):
- 1924412
- PAR ID:
- 10274326
- Date Published:
- Journal Name:
- Scientific Reports
- Volume:
- 10
- Issue:
- 1
- ISSN:
- 2045-2322
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1038/s41598-020-78649-9
