Enhancing the Light-Extraction Efficiency of AlGaN Nanowires Ultraviolet Light-Emitting Diode by using Nitride/Air Distributed Bragg Reflector Nanogratings
AuthorsAlias, Mohd Sharizal
Alhamoud, Abdullah A.
Alanazi, Lafi M.
Alatawi, Abdullah A.
Albadri, Abdulrahman M.
Alyamani, Ahmed Y.
Ng, Tien Khee
Ooi, Boon S.
KAUST DepartmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
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AbstractThe performance and efficiency of AlGaN ultraviolet light-emitting diodes have been limited by the extremely low light-extraction efficiency (LEE) due to the intrinsic material properties of AlGaN. Here, to enhance the LEE of the device, we demonstrate an AlGaN nanowires light-emitting diode (NWs-LED) integrated with nitride/air Distributed Bragg Reflector (DBR) nanogratings. Compared to a control device (only mesa), the AlGaN NWs-LED with the nitride/air DBR nanogratings exhibit enhancement in the light output power and external quantum efficiency (EQE) by a factor of ∼1.67. The higher light output power and EQE are attributed mainly to the multiple reflectances laterally for the transverse magnetic (TM)-polarized light and scattering introduced by the nanogratings. To further understand the LEE enhancement, the electrical field distribution, extraction ratio and polar pattern of the AlGaN NWs-LED with and without the nitride/air DBR nanogratings were analyzed using the finite-difference-time-domain method. It was observed that the TM-field emission was confined and scattered upward whereas the polar pattern was intensified for the AlGaN NWs-LED with the nanogratings. Our approach to enhance the LEE via the nitride/air DBR nanogratings can provide a promising route for increasing the efficiency of AlGaN-based LEDs, also, to functioning as facet mirror for AlGaN-based laser diodes.
CitationAlias MS, Janjua B, Zhao C, Priante D, Alhamoud AA, et al. (2017) Enhancing the Light-Extraction Efficiency of AlGaN Nanowires Ultraviolet Light-Emitting Diode by using Nitride/Air Distributed Bragg Reflector Nanogratings. IEEE Photonics Journal: 1–1. Available: http://dx.doi.org/10.1109/jphot.2017.2749198.
SponsorsThis publication is based upon work supported by the King Abdulaziz City for Science and Technology (KACST), Grant No. KACST TIC R2-FP-008, and the King Abdullah University of Science and Technology (KAUST) baseline funding BAS/1/1614-01-01.
JournalIEEE Photonics Journal