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Nallasani UR, Wu SK, Diep NQ, Lin YY, Wen HC, Chou WC, Chia CH. Structural and surface characterizations of 2D β-In 2Se 3/3D β-Ga 2O 3 heterostructures grown on c-Sapphire substrates by molecular beam epitaxy. Sci Rep 2024; 14:5146. [PMID: 38429525 PMCID: PMC10907755 DOI: 10.1038/s41598-024-55830-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 02/28/2024] [Indexed: 03/03/2024] Open
Abstract
Integrating two-dimensional (2D) layered materials with wide bandgap β-Ga2O3 has unveiled impressive opportunities for exploring novel physics and device concepts. This study presents the epitaxial growth of 2D β-In2Se3/3D β-Ga2O3 heterostructures on c-Sapphire substrates by plasma-assisted molecular beam epitaxy. Firstly, we employed a temperature-dependent two-step growth process to deposit Ga2O3 and obtained a phase-pure ( 2 ¯ 01 ) β-Ga2O3 film on c-Sapphire. Interestingly, the in-situ reflective high-energy electron diffraction (RHEED) patterns observed from this heterostructure revealed the in-plane 'b' lattice constant of β-Ga2O3 ~ 3.038Å. In the next stage, for the first time, 2D In2Se3 layers were epitaxially realized on 3D β-Ga2O3 under varying substrate temperatures (Tsub) and Se/In flux ratios (RVI/III). The deposited layers exhibited (00l) oriented β-In2Se3 on ( 2 ¯ 01 ) β-Ga2O3/c-Sapphire with the epitaxial relationship of [ 11 2 ¯ 0 ] β-In2Se3 || [010] β-Ga2O3 and [ 10 1 ¯ 0 ] β-In2Se3 || [102] β-Ga2O3 as observed from the RHEED patterns. Also, the in-plane 'a' lattice constant of β-In2Se3 was determined to be ~ 4.027Å. The single-phase β-In2Se3 layers with improved structural and surface quality were achieved at a Tsub ~ 280 °C and RVI/III ~ 18. The microstructural and detailed elemental analysis further confirmed the epitaxy of 2D layered β-In2Se3 on 3D β-Ga2O3, a consequence of the quasi-van der Waals epitaxy. Furthermore, the β-Ga2O3 with an optical bandgap (Eg) of ~ 5.04 eV (deep ultraviolet) when integrated with 2D β-In2Se3, Eg ~ 1.43eV (near infra-red) can reveal potential applications in the optoelectronic field.
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Affiliation(s)
- Umeshwar Reddy Nallasani
- Department of Electrophysics, College of Science, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu, 300093, Taiwan, ROC
| | - Ssu-Kuan Wu
- Department of Electrophysics, College of Science, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu, 300093, Taiwan, ROC
| | - Nhu Quynh Diep
- Department of Electrophysics, College of Science, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu, 300093, Taiwan, ROC
| | - Yen-Yu Lin
- Department of Electrophysics, College of Science, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu, 300093, Taiwan, ROC
| | - Hua-Chiang Wen
- Department of Electrophysics, College of Science, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu, 300093, Taiwan, ROC
| | - Wu-Ching Chou
- Department of Electrophysics, College of Science, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu, 300093, Taiwan, ROC.
| | - Chin-Hau Chia
- Department of Applied Physics, National University of Kaohsiung, 700 Kaohsiung University Road, Kaohsiung, 81148, Taiwan, ROC
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Petkov A, Mishra A, Cattelan M, Field D, Pomeroy J, Kuball M. Electrical and thermal characterisation of liquid metal thin-film Ga[Formula: see text]O[Formula: see text]-SiO[Formula: see text] heterostructures. Sci Rep 2023; 13:3437. [PMID: 36859432 PMCID: PMC9978026 DOI: 10.1038/s41598-023-30638-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/27/2023] [Indexed: 03/03/2023] Open
Abstract
Heterostructures of Ga[Formula: see text]O[Formula: see text] with other materials such as Si, SiC or diamond, are a possible way of addressing the low thermal conductivity and lack of p-type doping of Ga[Formula: see text]O[Formula: see text] for device applications, as well as of improving device reliability. In this work we study the electrical and thermal properties of Ga[Formula: see text]O[Formula: see text]-SiO[Formula: see text] heterostructures. Here, thin-film gallium oxide with thickness ranging between 8 and 30 nm was deposited onto a silicon substrate with a thermal oxide by means of oxidised liquid gallium layer delamination. The resulting heterostructure is then characterised by means of X-ray photoelectron spectroscopy and transient thermoreflectance. The thin-film gallium oxide valence band offset with respect to the SiO[Formula: see text] is measured as 0.1 eV and predicted as [Formula: see text] eV with respect to diamond. The thin-film's out-of-plane thermal conductivity is determined to be 3 ±0.5 Wm[Formula: see text] K[Formula: see text], which is higher than what has been previously measured for other polycrystalline Ga[Formula: see text]O[Formula: see text] films of comparable thickness.
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Affiliation(s)
- Alexander Petkov
- HH Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, UK
| | - Abhishek Mishra
- HH Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, UK
| | - Mattia Cattelan
- School of Chemistry, University of Bristol, Cantocks Close, Bristol, BS8 1TS, UK
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131, Padova, Italy
| | - Daniel Field
- HH Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, UK
| | - James Pomeroy
- HH Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, UK
| | - Martin Kuball
- HH Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, UK.
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Muhmood T, Cai Z, Lin S, Xiao J, Hu X, Ahmad F. Graphene/graphitic carbon nitride decorated with AgBr to boost photoelectrochemical performance with enhanced catalytic ability. NANOTECHNOLOGY 2020; 31:505602. [PMID: 33006324 DOI: 10.1088/1361-6528/abb48a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A novel graphene nanoplatelets (GNP) bridge between two semiconductors (AgBr and graphitic carbon nitride) was created to boost photoelectrochemical performance. The heterojunction created makes the whole system a Z-scheme catalyst. For the construction of this catalyst, the syringe pump methodology was adopted and different analytical techniques were used for the confirmation of structure and morphology. High angle annular dark field (HAADF), dark field (DF), DF-4 and DF-2 techniques, using Z-contrast phenomena, confirmed the heterostructure (ABGCN) and its composition. The constructed structure showed an enhanced photoelectrochemical and catalytic property against 'acute toxicity category-III (MM)' and 'category-IV (tetracycline hydrochloride (TH))' organic pollutants. The constructed catalyst degraded the MM in 57 min and the TH in 35 min with degradation rates of 0.01489 min-1 and 0.02387 min-1, respectively, due to the accumulation of photogenerated electrons on the conduction band (CB) of g-C3N4 and photogenerated holes on the valence band (VB) of AgBr by the transformation of charges through the graphene bridge. An ion trapping study also revealed that ·O2 and h+ were the active species which actively participated in the photocatalytic reaction.
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Affiliation(s)
- Tahir Muhmood
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering (SMSE), Shanghai JiaoTong University, Shanghai 200240, People's Republic of China
| | - Zihe Cai
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering (SMSE), Shanghai JiaoTong University, Shanghai 200240, People's Republic of China
| | - Shengxuan Lin
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering (SMSE), Shanghai JiaoTong University, Shanghai 200240, People's Republic of China
| | - Jiajia Xiao
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering (SMSE), Shanghai JiaoTong University, Shanghai 200240, People's Republic of China
| | - Xiaobin Hu
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering (SMSE), Shanghai JiaoTong University, Shanghai 200240, People's Republic of China
| | - Farooq Ahmad
- Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing, People's Republic of China
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