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Xue Y, Titze M, Mack J, Yang Z, Zhang L, Su SS, Zhang Z, Fan L. Selective Generation of V2 Silicon Vacancy Centers in 4H-Silicon Carbide. Nano Lett 2024; 24:2369-2375. [PMID: 38348823 DOI: 10.1021/acs.nanolett.3c03905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
The deterministic generation of individual color centers with defined orientations or types in solid-state systems is paramount for advancements in quantum technologies. Silicon vacancies in 4H-silicon carbide (4H-SiC) can be formed in V1 and V2 types. However, silicon vacancies are typically generated randomly between V1 and V2 types with similar probabilities. Here, we show that the preferred V2 centers can be selectively generated by focused ion beam (FIB) implantation on the m-plane in 4H-SiC. When implantation is on the m-plane (a-plane), the generation probability ratio between V1 and V2 centers increase exponentially (remains constant) with decreasing FIB fluences. With a fluence of 10 ions/spot, the probability to generate V2 centers is seven times higher than V1 centers. Our results represent a critical step toward the deterministic creation of specific defect types.
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Affiliation(s)
- Yongzhou Xue
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, United States
| | - Michael Titze
- Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - John Mack
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, United States
| | - Zhaohui Yang
- Department of Electrical and Computer Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Liang Zhang
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, United States
| | - Shei S Su
- Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Zheshen Zhang
- Department of Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Linran Fan
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, United States
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Wan G, Yang C, Zhao W, Li Q, Wang N, Li T, Zhou H, Chen H, Shi J. Anion-Regulated Selective Generation of Cobalt Sites in Carbon: Toward Superior Bifunctional Electrocatalysis. Adv Mater 2017; 29:1703436. [PMID: 29105848 DOI: 10.1002/adma.201703436] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 07/19/2017] [Indexed: 06/07/2023]
Abstract
The introduction of active transition metal sites (TMSs) in carbon enables the synthesis of noble-metal-free electrocatalysts for clean energy conversion applications; however, there are often multiple existing forms of TMSs, which are of different natures and catalytic models. Regulating the evolution of distinctive TMSs is highly desirable but remains challenging to date. Anions, as essential elements involved in the synthesis, have been totally neglected previously in the construction of TMSs. Herein, the effects of anions on the creation of different types of TMSs are investigated for the first time. It is found that the active cobalt-nitrogen sites tend to be selectively constructed on the surface of N-doped carbon by using chloride, while metallic cobalt nanoparticles encased in protective graphite layers are the dominant forms of cobalt species with nitrate ions. The obtained catalysts demonstrate cobalt-sites-dependent activity for oxygen reduction reaction and hydrogen evolution reaction in acidic media. The remarkably enhanced catalytic activities approaching that of benchmark Pt/C in an acidic medium have been obtained on the catalyst dominated with cobalt-nitrogen sites, confirmed by the advanced spectroscopic characterization. This finding demonstrates a general paradigm of anion-regulated evolution of distinctive TMSs, providing a new pathway for enhancing performances of various targeted reactions related with TMSs.
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Affiliation(s)
- Gang Wan
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road, Shanghai, 200050, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Ce Yang
- Chemical Science and Engineering Division, Argonne National Laboratory, 9700 Cass Avenue, Lemont, IL, 60439, USA
| | - Wanpeng Zhao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road, Shanghai, 200050, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Qianru Li
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road, Shanghai, 200050, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Ning Wang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road, Shanghai, 200050, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Tao Li
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, 9700 Cass Avenue, Lemont, IL, 60439, USA
| | - Hua Zhou
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, 9700 Cass Avenue, Lemont, IL, 60439, USA
| | - Hangrong Chen
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road, Shanghai, 200050, P. R. China
| | - Jianlin Shi
- State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Ding-xi Road, Shanghai, 200050, P. R. China
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