Controllable growth of vertical heterostructure GaTexSe1-x/Si by molecular beam epitaxy

Liu, Shanshan and Yuan, Xiang and Wang, Peng and Chen, Zhi Gang and Tang, Lei and Zhang, Enze and Zhang, Cheng and Liu, Yanwen and Wang, Weiyi and Liu, Cong and Chen, Chen and Zou, Jin and Hu, Weida and Xiu, Faxian (2015) Controllable growth of vertical heterostructure GaTexSe1-x/Si by molecular beam epitaxy. ACS Nano, 9 (8). pp. 8592-8598. ISSN 1936-0851

Abstract

Two dimensional (2D) alloys, especially transition metal dichalcogenides, have attracted intense attention owing to their band-gap tunability and potential optoelectrical applications. Here, we report the controllable synthesis of wafer-scale, few-layer GaTexSe1–x alloys (0 ≤ x ≤ 1) by molecular beam epitaxy (MBE). We achieve a layer-by-layer growth mode with uniform distribution of Ga, Te, and Se elements across 2 in. wafers. Raman spectroscopy was carried out to explore the composition-dependent vibration frequency of phonons, which matches well with the modified random-element-isodisplacement model. Highly efficient photodiode arrays were also built by depositing few-layer GaTe0.64Se0.36 on n-type Si substrates. These p–n junctions have steady rectification characteristics with a rectifying ratio exceeding 300 and a high external quantum efficiency around 50%. We further measured more devices on MBE-grown GaTexSe1–x/Si heterostructures across the full range to explore the composition-dependent external quantum efficiency. Our study opens a new avenue for the controllable growth of 2D alloys with wafer-scale homogeneity, which is a prominent challenge in 2D material research.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty / Department / School: No Faculty
Date Deposited: 21 Jun 2017 04:07
Last Modified: 21 Jun 2017 04:09
Uncontrolled Keywords: GaTexSe1-x; two-dimensional alloy; homogeneity; molecular beam epitaxy;
Fields of Research : 09 Engineering > 0912 Materials Engineering > 091299 Materials Engineering not elsewhere classified
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering
Identification Number or DOI: 10.1021/acsnano.5b03796
URI: http://eprints.usq.edu.au/id/eprint/31680

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