Crystallize It before It diffuses
- Numerous phosphorus-rich metal phosphides containing both P-P bonds and metal-P bonds are known from the solid-state chemistry literature. A method to grow these materials in thin-film form would be desirable, as thin films are required in many applications and they are an ideal platform for high-throughput studies. In addition, the high density and smooth surfaces achievable in thin films are a significant advantage for characterization of transport and optical properties. Despite these benefits, there is hardly any published work on even the simplest binary phosphorus-rich phosphide films. Here, we demonstrate growth of single-phase CuP2 films by a two-step process involving reactive sputtering of amorphous CuP2+x and rapid annealing in an inert atmosphere. At the crystallization temperature, CuP2 is thermodynamically unstable with respect to Cu3P and P-4. However, CuP2 can be stabilized if the amorphous precursors are mixed on the atomic scale and are sufficiently close to the desired composition (neither too P poor nor too PNumerous phosphorus-rich metal phosphides containing both P-P bonds and metal-P bonds are known from the solid-state chemistry literature. A method to grow these materials in thin-film form would be desirable, as thin films are required in many applications and they are an ideal platform for high-throughput studies. In addition, the high density and smooth surfaces achievable in thin films are a significant advantage for characterization of transport and optical properties. Despite these benefits, there is hardly any published work on even the simplest binary phosphorus-rich phosphide films. Here, we demonstrate growth of single-phase CuP2 films by a two-step process involving reactive sputtering of amorphous CuP2+x and rapid annealing in an inert atmosphere. At the crystallization temperature, CuP2 is thermodynamically unstable with respect to Cu3P and P-4. However, CuP2 can be stabilized if the amorphous precursors are mixed on the atomic scale and are sufficiently close to the desired composition (neither too P poor nor too P rich). Fast formation of polycrystalline CuP2, combined with a short annealing time, makes it possible to bypass the diffusion processes responsible for decomposition. We find that thin-film CuP2 is a 1.5 eV band gap semiconductor with interesting properties, such as a high optical absorption coefficient (above 10(5) cm(-1)), low thermal conductivity (1.1 W/(K m)), and composition-insensitive electrical conductivity (around 1 S/cm). We anticipate that our processing route can be extended to other phosphorus-rich phosphides that are still awaiting thin-film synthesis and will lead to a more complete understanding of these materials and of their potential applications.…
Author details: | Andrea CrovettoORCiD, Danny KojdaORCiD, Feng YiORCiD, Karen N. HeinselmanORCiD, David A. LaVan, Klaus HabichtORCiDGND, Thomas UnoldORCiD, Andriy ZakutayevORCiD |
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DOI: | https://doi.org/10.1021/jacs.2c04868 |
ISSN: | 0002-7863 |
ISSN: | 1520-5126 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/35822809 |
Title of parent work (English): | Journal of the american chemical society |
Subtitle (English): | kinetic stabilization of thin-film phosphorus-rich semiconductor CuP2 |
Publisher: | American Chemical Society |
Place of publishing: | Washington |
Publication type: | Article |
Language: | English |
Date of first publication: | 2022/07/13 |
Publication year: | 2022 |
Release date: | 2024/05/30 |
Volume: | 144 |
Issue: | 29 |
Number of pages: | 10 |
First page: | 13334 |
Last Page: | 13343 |
Funding institution: | European Unions Horizon 2020 research and innovation programme under the; Marie Sklodowska-Curie Grant [840751]; U.S. Department of Energy (DOE); [DE-AC36-08GO28308]; Office of Science, Office of Basic Energy Sciences;; Helmholtz Energy Materials Foundry (HEMF) |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Peer review: | Referiert |
Publishing method: | Open Access / Hybrid Open-Access |
License (German): | CC-BY - Namensnennung 4.0 International |