Electronic and optical modulation of pine tree-like nanostructures of gallium nitride

• Main Authors: Saleem, Umar, Tjahjana, Liliana, Arramel, Ahmad, Faozan, Hardhienata, Hendradi, Maddalena, Francesco, Birowosuto, Muhammad Danang, Wang, Hong
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Materials; Nanowires; Growth
• Online Access: https://hdl.handle.net/10356/160169
• Institution: Nanyang Technological University

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 anE2Hpeak at 570 ± 6 cm-1which 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.