We report on the illustration of the first electron blocking layer (EBL) free AlInN nanowire light-emitting diodes (LEDs) operating in the deep ultraviolet (DUV) wavelength region (sub-250 nm). We have systematically analyzed the results using APSYS software and compared with simulated AlGaN nanowire DUV LEDs. From the simulation results, significant efficiency droop was observed in AlGaN based devices, attributed to the significant electron leakage. However, compared to AlGaN nanowire DUV LEDs at similar emission wavelength, the proposed single quantum well (SQW) AlInN based light-emitters offer higher internal quantum efficiency without droop up to current density of 1500 A/cm2and high output optical power. Moreover, we find that transverse magnetic polarized emission is ∼ 5 orders stronger than transverse electric polarized emission at 238 nm wavelength. Further research shows that the performance of the AlInN DUV nanowire LEDs decreases with multiple QWs in the active region due to the presence of the non-uniform carrier distribution in the active region. This study provides important insights on the design of new type of high performance AlInN nanowire DUV LEDs, by replacing currently used AlGaN semiconductors.
Nanowire AlGaN III‐nitride LEDs are claimed as potential high‐efficiency solid‐state photon sources spanning to the short‐wavelength deep ultraviolet (UV). Nanowire LEDs (NWLEDs) emitting in the UV are compared with a transparent n‐AlGaN top electrode formed by coalescing the top region of nanowire–ensemble LEDs with commonly employed opaque conformal metallic electrodes used for nanowire‐based devices. The use of a transparent contact results in an increase in the wall plug efficiency of >25×, exceeding the expected increase due to enhanced photon‐extraction efficiency. Increased nanowire connectivity reduces the short‐circuit pathways, enabling higher device yields of relatively large‐area (>1 mm2) UV nanowire–ensemble LEDs. Despite these large relative improvements, the absolute output efficiency remains miniscule (<1 m%). Electroluminescence microscopy demonstrates that <0.1% of nanowires within the ensemble contribute to emission. The single‐nanowire efficiency is estimated and points toward improvement of the homogeneity of the injection current as a crucial step for realizing commercially viable UV NWLEDs.
more » « less- NSF-PAR ID:
- 10482079
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- physica status solidi (RRL) – Rapid Research Letters
- ISSN:
- 1862-6254
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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