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Published on: December 7, 2017
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InP nanowire light-emitting diodes with different pn-junction structures.
S Kimura1, H Gamo1, Y Katsumi1
1Graduate School of Information Science and Technology and Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, Japan.
Nanotechnology
|April 8, 2022
Summary
Radial pn junctions in indium phosphide nanowire light-emitting diodes (LEDs) offer better current injection and are suitable for device applications. Electroluminescence originates from zinc-blende, wurtzite phases, and their heterojunction.
Area of Science:
- Materials Science
- Semiconductor Physics
- Nanotechnology
Background:
- Indium phosphide (InP) nanowires (NWs) are promising for optoelectronic devices.
- Wurtzite (WZ) and zinc-blende (ZB) phases in InP NWs influence their properties.
- Understanding pn junction configurations is crucial for nanowire light-emitting diodes (LEDs).
Purpose of the Study:
- To characterize wurtzite InP nanowire LEDs with axial and radial pn junctions.
- To compare the performance of radial versus axial pn junctions for current injection.
- To analyze the electroluminescence (EL) properties and their origins.
Main Methods:
- Fabrication and characterization of InP nanowire LEDs with different pn junction types.
- Measurement of series resistance to assess current injection efficiency.
- Electroluminescence spectroscopy to identify emission peaks.
- Transmission electron microscopy (TEM) for structural analysis.
Main Results:
- Radial pn junctions exhibited lower series resistance than axial pn junctions, indicating superior current injection.
- Electroluminescence spectra showed three distinct peaks corresponding to the ZB phase, WZ phase, and ZB/WZ heterojunction.
- TEM analysis revealed that the dominant EL emission in radial pn junction devices originated from the ZB/WZ interface.
Conclusions:
- Radial pn junctions are more suitable for efficient current injection in InP NW LEDs.
- The interplay between ZB and WZ phases, particularly at heterojunctions, significantly impacts EL properties.
- Interface engineering at stacking faults is key for optimizing light emission in InP NW LEDs.
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