Gallium nitride nanofiber

Catalog	ACMA00031048
Description	The nanofiber can show peculiar shapes. Sometimes they can show noncrystalline order, assuming e.g. a pentagonal symmetry or a helicoidal (spiral) shape. Electrons zigzag along pentagonal tubes and spiral along helicoidal tubes. The lack of crystalline order is due to the fact that a nanofiber is periodic only in one dimension (along its axis). Hence it can assume any order in the other directions (in plane) if this is energetically favorable. Arrays of nanofiber / nanowhiskers are a new type of nanostructures that exhibit quasi-1D characteristics. Metallic nanofiber / nanowhiskers and multi-layered nanofiber / nanowhiskers have been successfully fabricated before.
Application	There are many applications where nanowires may become important in electronic, opto-electronic and nanoelectromechanical devices, as additives in advanced composites, for metallic interconnects in nanoscale quantum devices, as field-emittors and as leads for biomolecular nanosensors. Also optical, sensing, solar cells, magnetic, and electronic device applications
Material	Gallium nitride
Notes	Before using nanofibers, the user shall determine the suitability of the product for its intended use, and user assumes all risk and liability whatsoever in connection therewith.
Packaging	Usually to customer specification
Specification	Presently diameters nominally as small as 12 nanometers

Case Study

Advancing Self-Powered UV Detection with Electrospun Gallium Nitride Nanofibers

Zhang, Mingxiang, et al. Applied Surface Science 452 (2018): 43-48.

Electrospun gallium nitride nanowires (GaN-NWs) were engineered as photoanodes in this work to replace GaN-P. The one-dimensional nanostructure provides direct transport channels for photogenerated carriers, enhancing device kinetics.
Preparation:
· Electrospinning: Gallium nitrate (2.0g) in 10 wt% PVP/alcohol-water solution as precursor for electrospinning. Parameters: 0.5 mL/h flow rate, 20 kV voltage, 20 cm needle-to-collector distance.
· Calcination: Step 1: 900°C in air (1 h, 2°C/min ramp) → Ga₂O₃ nanofibers; Step 2: 900°C in NH₃ (1 h, 2°C/min ramp) → GaN-NWs.
· Device Fabrication: GaN-NWs dispersed in acetic acid/water/ethanol; PEG-added paste drop-coated on FTO glass; Sintered at 450°C (30 min) → assembled into PEC cells.
Key Findings:
· Electrospun GaN-NWs showed intrinsically improved performance as the 1D structure allowed for direct transport channels of the photogenerated carriers.
· The resulting device showed significantly higher V_oc and J_sc than GaN-P and could be operated as a UV sensor with rapid response of t_r = 0.28 s and t_d = 0.25 s, which are improvements by 27% and 17%, respectively.
· Photocurrent density as high as 10 μA cm^-2 was observed under UV illumination, and no degradation was found during testing over 80 days.

Enhancing Ethanol Sensing Performance with Electrospun Gallium Nitride Nanofibers

Luo, Xiaoju, et al. Sensors and Actuators B: Chemical 202 (2014): 1010-1018.

Porous gallium nitride nanofibers (GaN-NFs) were synthesized via electrospinning as a superior sensing material in this work, leveraging their one-dimensional porous nanostructure to enhance gas interaction dynamics.
Preparation:
· GaN-NF Synthesis: Ga(NO3)3·xH2O / H2O / ethanol (1:4:4 mass ratio) + PVP were employed as precursor for electrospinning at 20 kV voltage. The obtained composite nanofibers were calcinated at 900°C (2h, 2°C/min ramp) to prepare Ga2O3 nanofibers. Then, Ga2O3 nanofibers were ammoniated at 850°C (2h, 2°C/min) under NH3, resulting GaN-NFs.
· GaN-NP Synthesis (Control): GaN-NPs were prepared by sol-gel method using the same precursor and the same calcination/ammoniation scheme.
· Sensor Fabrication: Side-heated sensor structure. Comparative testing: 280-360°C operating range, 50-1000 ppm ethanol.
Key Findings:
The porous GaN-NFs demonstrated significantly enhanced ethanol sensing capabilities versus GaN-NPs:
· Higher Response Magnitude: Superior sensitivity across tested concentrations.
· Faster Kinetics: Shorter response time at optimal 320°C operating temperature.
· Enhanced Selectivity: Improved discrimination against interfering gases.
· Structural Advantage: 1D porous architecture maximizes surface-reactant interaction.