The structural properties of GeSn thin films with different Sn concentrations and thicknesses grown on Ge (001) by molecular beam epitaxy (MBE) and on Ge-buffered Si (001) wafers by chemical vapor deposition (CVD) were analyzed through high resolution X-ray diffraction and cross-sectional transmission electron microscopy. Two-dimensional reciprocal space maps around the asymmetric (224) reflection were collected by X-ray diffraction for both the whole structures and the GeSn epilayers. The broadenings of the features of the GeSn epilayers with different relaxations in the direction, along the -2 direction and parallel to the surface were investigated. The dislocations were identified by transmission electron microscopy. Threading dislocations were found in MBE grown GeSn layers, but not in the CVD grown ones. The point defects and dislocations were two possible reasons for the poor optical properties in the GeSn alloys grown by MBE.
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http://dx.doi.org/10.3390/ma13163645 | DOI Listing |
Sensors (Basel)
February 2024
Department of Mechanical Engineering, and Advanced Institute of Manufacturing with High-Tech Innovations (AIM-HI), National Chung Cheng University, Chiayi 621301, Taiwan.
GeSn alloys have recently emerged as complementary metal-oxide-semiconductor (CMOS)-compatible materials for optoelectronic applications. Although various photonic devices based on GeSn thin films have been developed, low-dimensional GeSn quantum structures with improved efficiencies hold great promise for optoelectronic applications. This study theoretically analyses Ge-capped GeSn pyramid quantum dots (QDs) on Ge substrates to explore their potential for such applications.
View Article and Find Full Text PDFNanomaterials (Basel)
February 2023
Research and Development Center of Optoelectronic Hybrid IC, Guangdong Greater Bay Area Institute of Integrated Circuit and System, Guangzhou 510535, China.
Among photodetectors, avalanche photodiodes (APDs) have an important place due to their excellent sensitivity to light. APDs transform photons into electrons and then multiply the electrons, leading to an amplified photocurrent. APDs are promising for faint light detection owing to this outstanding advantage, which will boost LiDAR applications.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2022
Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk, Russia.
High-performance p-type thin-film transistors (pTFTs) are crucial for realizing low-power display-on-panel and monolithic three-dimensional integrated circuits. Unfortunately, it is difficult to achieve a high hole mobility of greater than 10 cm/V·s, even for SnO TFTs with a unique single-hole band and a small hole effective mass. In this paper, we demonstrate a high-performance GeSn pTFT with a high field-effect hole mobility (μ), of 41.
View Article and Find Full Text PDFNano Lett
December 2021
Department of Engineering Physics, École Polytechnique de Montréal, C.P. 6079, Succ. Centre-Ville, Montreal, Québec H3C 3A7, Canada.
Using GeSn semiconductor as a model system, this work unravels the atomic-level details of the behavior of solutes in the vicinity of a dislocation prior to surface segregation in strained, metastable thin layers. The dislocations appear in the 3D atom probe tomography maps as columnar regions, 3.5-4.
View Article and Find Full Text PDFNanomaterials (Basel)
September 2021
Key Laboratory of Microelectronic Devices Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China.
GeSn alloys have already attracted extensive attention due to their excellent properties and wide-ranging electronic and optoelectronic applications. Both theoretical and experimental results have shown that direct bandgap GeSn alloys are preferable for Si-based, high-efficiency light source applications. For the abovementioned purposes, molecular beam epitaxy (MBE), physical vapour deposition (PVD), and chemical vapor deposition (CVD) technologies have been extensively explored to grow high-quality GeSn alloys.
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