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Two-Dimensional Gallium Sulfide Nanoflakes for UV-Selective Photoelectrochemical-type Photodetectors
[Image: see text] Two-dimensional (2D) transition-metal monochalcogenides have been recently predicted to be potential photo(electro)catalysts for water splitting and photoelectrochemical (PEC) reactions. Differently from the most established InSe, GaSe, GeSe, and many other monochalcogenides, bulk...
Autores principales: | , , , , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical
Society
2021
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8279705/ https://www.ncbi.nlm.nih.gov/pubmed/34276861 http://dx.doi.org/10.1021/acs.jpcc.1c03597 |
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author | Zappia, Marilena I. Bianca, Gabriele Bellani, Sebastiano Curreli, Nicola Sofer, Zdeněk Serri, Michele Najafi, Leyla Piccinni, Marco Oropesa-Nuñez, Reinier Marvan, Petr Pellegrini, Vittorio Kriegel, Ilka Prato, Mirko Cupolillo, Anna Bonaccorso, Francesco |
author_facet | Zappia, Marilena I. Bianca, Gabriele Bellani, Sebastiano Curreli, Nicola Sofer, Zdeněk Serri, Michele Najafi, Leyla Piccinni, Marco Oropesa-Nuñez, Reinier Marvan, Petr Pellegrini, Vittorio Kriegel, Ilka Prato, Mirko Cupolillo, Anna Bonaccorso, Francesco |
author_sort | Zappia, Marilena I. |
collection | PubMed |
description | [Image: see text] Two-dimensional (2D) transition-metal monochalcogenides have been recently predicted to be potential photo(electro)catalysts for water splitting and photoelectrochemical (PEC) reactions. Differently from the most established InSe, GaSe, GeSe, and many other monochalcogenides, bulk GaS has a large band gap of ∼2.5 eV, which increases up to more than 3.0 eV with decreasing its thickness due to quantum confinement effects. Therefore, 2D GaS fills the void between 2D small-band-gap semiconductors and insulators, resulting of interest for the realization of van der Waals type-I heterojunctions in photocatalysis, as well as the development of UV light-emitting diodes, quantum wells, and other optoelectronic devices. Based on theoretical calculations of the electronic structure of GaS as a function of layer number reported in the literature, we experimentally demonstrate, for the first time, the PEC properties of liquid-phase exfoliated GaS nanoflakes. Our results indicate that solution-processed 2D GaS-based PEC-type photodetectors outperform the corresponding solid-state photodetectors. In fact, the 2D morphology of the GaS flakes intrinsically minimizes the distance between the photogenerated charges and the surface area at which the redox reactions occur, limiting electron–hole recombination losses. The latter are instead deleterious for standard solid-state configurations. Consequently, PEC-type 2D GaS photodetectors display a relevant UV-selective photoresponse. In particular, they attain responsivities of 1.8 mA W(–1) in 1 M H(2)SO(4) [at 0.8 V vs reversible hydrogen electrode (RHE)], 4.6 mA W(–1) in 1 M Na(2)SO(4) (at 0.9 V vs RHE), and 6.8 mA W(–1) in 1 M KOH (at 1.1. V vs RHE) under 275 nm illumination wavelength with an intensity of 1.3 mW cm(–2). Beyond the photodetector application, 2D GaS-based PEC-type devices may find application in tandem solar PEC cells in combination with other visible-sensitive low-band-gap materials, including transition-metal monochalcogenides recently established for PEC solar energy conversion applications. |
format | Online Article Text |
id | pubmed-8279705 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | American Chemical
Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-82797052021-07-15 Two-Dimensional Gallium Sulfide Nanoflakes for UV-Selective Photoelectrochemical-type Photodetectors Zappia, Marilena I. Bianca, Gabriele Bellani, Sebastiano Curreli, Nicola Sofer, Zdeněk Serri, Michele Najafi, Leyla Piccinni, Marco Oropesa-Nuñez, Reinier Marvan, Petr Pellegrini, Vittorio Kriegel, Ilka Prato, Mirko Cupolillo, Anna Bonaccorso, Francesco J Phys Chem C Nanomater Interfaces [Image: see text] Two-dimensional (2D) transition-metal monochalcogenides have been recently predicted to be potential photo(electro)catalysts for water splitting and photoelectrochemical (PEC) reactions. Differently from the most established InSe, GaSe, GeSe, and many other monochalcogenides, bulk GaS has a large band gap of ∼2.5 eV, which increases up to more than 3.0 eV with decreasing its thickness due to quantum confinement effects. Therefore, 2D GaS fills the void between 2D small-band-gap semiconductors and insulators, resulting of interest for the realization of van der Waals type-I heterojunctions in photocatalysis, as well as the development of UV light-emitting diodes, quantum wells, and other optoelectronic devices. Based on theoretical calculations of the electronic structure of GaS as a function of layer number reported in the literature, we experimentally demonstrate, for the first time, the PEC properties of liquid-phase exfoliated GaS nanoflakes. Our results indicate that solution-processed 2D GaS-based PEC-type photodetectors outperform the corresponding solid-state photodetectors. In fact, the 2D morphology of the GaS flakes intrinsically minimizes the distance between the photogenerated charges and the surface area at which the redox reactions occur, limiting electron–hole recombination losses. The latter are instead deleterious for standard solid-state configurations. Consequently, PEC-type 2D GaS photodetectors display a relevant UV-selective photoresponse. In particular, they attain responsivities of 1.8 mA W(–1) in 1 M H(2)SO(4) [at 0.8 V vs reversible hydrogen electrode (RHE)], 4.6 mA W(–1) in 1 M Na(2)SO(4) (at 0.9 V vs RHE), and 6.8 mA W(–1) in 1 M KOH (at 1.1. V vs RHE) under 275 nm illumination wavelength with an intensity of 1.3 mW cm(–2). Beyond the photodetector application, 2D GaS-based PEC-type devices may find application in tandem solar PEC cells in combination with other visible-sensitive low-band-gap materials, including transition-metal monochalcogenides recently established for PEC solar energy conversion applications. American Chemical Society 2021-05-26 2021-06-10 /pmc/articles/PMC8279705/ /pubmed/34276861 http://dx.doi.org/10.1021/acs.jpcc.1c03597 Text en © 2021 The Authors. Published by American Chemical Society Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Zappia, Marilena I. Bianca, Gabriele Bellani, Sebastiano Curreli, Nicola Sofer, Zdeněk Serri, Michele Najafi, Leyla Piccinni, Marco Oropesa-Nuñez, Reinier Marvan, Petr Pellegrini, Vittorio Kriegel, Ilka Prato, Mirko Cupolillo, Anna Bonaccorso, Francesco Two-Dimensional Gallium Sulfide Nanoflakes for UV-Selective Photoelectrochemical-type Photodetectors |
title | Two-Dimensional Gallium Sulfide Nanoflakes for UV-Selective
Photoelectrochemical-type Photodetectors |
title_full | Two-Dimensional Gallium Sulfide Nanoflakes for UV-Selective
Photoelectrochemical-type Photodetectors |
title_fullStr | Two-Dimensional Gallium Sulfide Nanoflakes for UV-Selective
Photoelectrochemical-type Photodetectors |
title_full_unstemmed | Two-Dimensional Gallium Sulfide Nanoflakes for UV-Selective
Photoelectrochemical-type Photodetectors |
title_short | Two-Dimensional Gallium Sulfide Nanoflakes for UV-Selective
Photoelectrochemical-type Photodetectors |
title_sort | two-dimensional gallium sulfide nanoflakes for uv-selective
photoelectrochemical-type photodetectors |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8279705/ https://www.ncbi.nlm.nih.gov/pubmed/34276861 http://dx.doi.org/10.1021/acs.jpcc.1c03597 |
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