Abstract
The authors report upon the increased light-output power (Pout) via a reduction in the forward voltage (Vf) for nonpolar a -plane GaN LEDs using Ni/Al/Ni/Au n-type ohmic contacts. The specific contact resistivity of the Ni/Al/Ni/Au contact is found to be as low as 5.6 × 10-5 whereas that of a typical Ti/Al/Ni/Au contact is 6.8 × 10-4 Ω cm2, after annealing at 700 °C. The X-ray photoelectron spectroscopy results show that the upward surface band bending is less pronounced for the Ni/Al contact compared to the Ti/Al contact, leading to a decrease in the effective Schottky barrier height (SBH). The Vf of the nonpolar LEDs decreases by 10% and Pout increases by 15% when the Ni/Al/Ni/Au scheme is used instead of the typical Ti/Al/Ni/Au metal scheme.
Original language | English |
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Pages (from-to) | 274-276 |
Number of pages | 3 |
Journal | Physica Status Solidi - Rapid Research Letters |
Volume | 5 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2011 Aug |
Keywords
- Current injection
- LED
- Ni-Al alloys
- Nonpolar GaN
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics