We report a near-broken-gap alignment between p-type FeWO and n-type FeWO, a model pair for the realization of Ohmic direct junction thermoelectrics. Both undoped materials have a large Seebeck coefficient and high electrical conductivity at elevated temperatures, due to inherent electronic defects. A band-alignment diagram is proposed based on X-ray photoelectron and ultraviolet-visible light reflectance spectroscopy. Experimentally acquired nonrectifying - characteristics and the constructed band-alignment diagram support the proposed formation of a near-broken-gap junction. We have additionally performed computational modeling based on density functional theory (DFT) on bulk models of the individual compounds to rationalize the experimental band-alignment diagram and to provide deeper insight into the relevant band characteristics. The DFT calculations confirm an Fe-3d character of the involved band edges, which we suggest is a decisive feature for the unusual band overlap.
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http://dx.doi.org/10.1021/acsami.0c19341 | DOI Listing |
Chemistry
December 2024
Department of Chemistry, Egerton University, Njoro, Kenya.
Designing a high-performance solar cell structure requires the understanding of material innovation, device engineering, charge behavior, operation characteristics and efficient photoconversion of light to generate electricity. This study offers a detailed numerical evaluation of the device physics in a highly efficient methylammonium-based perovskite solar cell (PSC) of the configuration, FTO/WO/CH₃NH₃SnI₃/GO/Fe. Utilizing the SCAPS-1D device simulator, an impressive open-circuit voltage (V) of 1.
View Article and Find Full Text PDFPhys Chem Chem Phys
July 2024
Department of Physics, Shiv Nadar University, Greater Noida, Uttar Pradesh 201314, India.
The present investigation deals with the effect of a BaTiO (BTO) dielectric layer on the performance of MoS/p-Si heterojunction photodetectors. The MoS/p-Si junction demonstrates a responsivity of ∼80 A W and detectivity of ∼10 Jones. The inclusion of a dielectric BTO layer significantly enhances the performance of MoS/p-Si photodetectors, leading to a remarkable improvement with a very high responsivity of ∼603 A W and detectivity of ∼10 Jones.
View Article and Find Full Text PDFNat Commun
November 2023
Institute of Photoelectronic Thin Film Devices and Technology, State Key Laboratory of Photovoltaic Materials and Cells, Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin, Ministry of Education Engineering Research Center of Thin Film Photoelectronic Technology, Renewable Energy Conversion and Storage Center, Nankai University, 300350, Tianjin, China.
Cuprous oxide (CuO) is a promising oxide material for photoelectrochemical water splitting (PEC), and increasing its photovoltage is the key to creating efficient overall PEC water-splitting devices. Previous reports are mostly focused on optimizing the energy band alignment between CuO and the n-type buffer layer to improve the photovoltage of CuO photocathodes. However, the band alignment between the n-type buffer layer and the protective layer is often ignored.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2023
Laboratory of Acoustic Microscopy, Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119334 Moscow, Russia.
Chevrel non-van der Waals crystals are promising candidates for the fabrication of novel 2D materials due to their versatile crystal structure formed by covalently bonded (MoX) clusters (X-chalcogen atom). Here, we present a comprehensive theoretical study of the stability and properties of Mo-based Janus 2D structures with Chevrel structures consisting of chalcogen and halogen atoms via density functional theory calculations. Based on the analysis performed, we determined that the SMoI monolayer is the most promising structure for overall photocatalytic water-splitting application due to its appropriate band alignment and its ability to absorb visible light.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2022
Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Krakow 30-059, Poland.
Heterostructures of TiO@FeO with a specific electronic structure and morphology enable us to control the interfacial charge transport necessary for their efficient photocatalytic performance. In spite of the extensive research, there still remains a profound ambiguity as far as the band alignment at the interface of TiO@FeO is concerned. In this work, the extended type I heterojunction between anatase TiO nanocrystals and α-FeO hematite nanograins is proposed.
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