Electronic and Optical Modulation of Pine Tree-like Nanostructures of Gallium Nitride

• Published in: Journal of physical chemistry. C Vol. 125; no. 25; pp. 13917 - 13924
• Main Authors: Saleem, Umar, Tjahjana, Liliana, Arramel, Ahmad, Faozan, Hardhienata, Hendradi, Maddalena, Francesco, Birowosuto, M. Danang, Wang, Hong
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01.07.2021
• Subjects: C: Spectroscopy and Dynamics of Nano, Hybrid, and Low-Dimensional Materials
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.1c02819

We present the synthesis and characterization of gallium nitride (GaN) pine tree-like nanostructures (PTLNs) grown by low-pressure chemical vapor deposition. A high yield of PTLNs is densely arranged with each PTLN having a typical length of 15.46 ± 3.38 μm. From Raman spectroscopy, we observe an E 2 H peak at 570 ± 6 cm–1 which is the primary characteristic of wurtzite. X-ray and ultraviolet photoemission spectroscopy reveal that the electronic structures of GaN PTLNs indicate an n-type character, while the work function and valence band maximum are determined to be 3.30 ± 0.05 and 3.85 ± 0.08 eV, respectively. We confirm the electronic nature of our structure from the current–voltage characteristics exhibiting rectifying behavior. Density functional theory calculations of GaN PTLNs modeled by germanium-doped GaN nanowires are consistent with our experimental findings. To summarize, the energy-band diagram is presented for the future of GaN PTLNs in the optoelectronic and sensing applications.