Self-catalytic growth and characterization of AlGaN nanostructures with high Al composition

• Published in: Journal of materials science. Materials in electronics Vol. 33; no. 15; pp. 11906 - 11914
• Main Authors: Liu, Zitong, Shen, Longhai, Chen, Jianjin, Zhang, Xinglai
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2022; Springer Nature B.V
• Subjects: Aluminum gallium nitrides; Ammonia; Characterization and Evaluation of Materials; Chemical composition; Chemical vapor deposition; Chemistry and Materials Science; Materials Science; Nanorods; Nanostructure; Nucleation; Optical and Electronic Materials; Optoelectronic devices; Phase separation; Silicon substrates; Ternary alloys; Ternary systems
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-022-08152-6

AlGaN ternary alloy nanostructures have emerged as an important building block for optoelectronic devices and exhibit broad application prospects. However, the fabrication of AlGaN nanostructures with high quality, especially high Al composition, by chemical vapor deposition (CVD) is limited by their phase separation. Here, AlGaN ternary alloy nanostructures with Al/Ga atomic ratio more than 90% are synthesized by using CVD method. The AlGaN nanocones and nanorods are obtained by adjusting the Ar/NH 3 flow ratio at the same temperature. Furthermore, it is found that the increase of Ar flux is more favorable to the transport of Ga source, which leads to the raise of Ga content in AlGaN nanostructures. On the other hand, the decrease of NH 3 flow is conducive to the formation of nanorods. Moreover, the pre-deposited Al powder on Si substrate provides Al-rich growth conditions and nucleation sites for AlGaN nanostructures, which becomes the key to the formation of AlGaN nanostructures with high Al composition. Based on the evolution of morphology, the growth process of AlGaN nanostructures is investigated by a self-catalytic vapor–solid mechanism.