Abstract
Strong room-temperature electroluminescence at 365 nm has been demonstrated from simple Au/AlN/n-GaN metal-insulator-semiconductor (MIS) light emitting diodes, which do not contain p-doped material. Current-voltage and electroluminescence data indicate that an AlN insulating layer thickness of 10 nm results in optimized diode behavior and maximum ultraviolet emission: At lower thicknesses carriers tunnel easily through the barrier, whereas at greater thicknesses the forward resistivity is excessively high. A decrease in emission intensity was observed at high injection currents due to Fowler-Nordheim tunnelling. However the device efficiency was found to improve by a factor of 10 when the AlN layer and the metal contact layer were deposited without breaking vacuum, thereby preventing any contamination or oxidation of the AlN surface. Additionally, this MIS device showed clear resonant tunnelling characteristics which are correlated with the enhanced light emission intensity.
| Original language | English |
|---|---|
| Article number | 7947132 |
| Pages (from-to) | 1-8 |
| Number of pages | 8 |
| Journal | IEEE Photonics Journal |
| Volume | 9 |
| Issue number | 4 |
| Early online date | 13 Jun 2017 |
| DOIs | |
| Publication status | Published - 1 Aug 2017 |
Funding
This work was supported in part by EPSRC National Centre for III-V Technologies, in part by the Leverhulme Trust Research Leadership Award RL-2012-007, in part by the ERC Starting Grant SCOPE, and in part by EPSRC under Grant EP/I012591/1.
Keywords
- AlN/GaN
- electroluminescence
- metal-insulator-semiconductor device
- Resonant tunnelling diodes
- ultraviolet light emitting diodes
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering