Size-independent low voltage of InGaN micro-light-emitting diodes with epitaxial tunnel junctions using selective area growth by metalorganic chemical vapor deposition

TitleSize-independent low voltage of InGaN micro-light-emitting diodes with epitaxial tunnel junctions using selective area growth by metalorganic chemical vapor deposition
Publication TypeJournal Article
Year of Publication2020
AuthorsLi, P., H. Zhang, H. Li, M. Iza, Y. Yao, M. S. Wong, N. Palmquist, J. S. Speck, S. Nakamura, and S. P. DenBaars
JournalOpt. Express
Volume28
Pagination18707–18712
Date PublishedJun
KeywordsChemical vapor deposition, Diode lasers, Indium tin oxide, light emitting diodes, Organic light emitting diodes, Vertical cavity surface emitting lasers
Abstract

High performance InGaN micro-size light-emitting diodes (µLEDs) with epitaxial tunnel junctions (TJs) were successfully demonstrated using selective area growth (SAG) by metalorganic chemical vapor deposition (MOCVD). Patterned n + GaN/n-GaN layers with small holes were grown on top of standard InGaN blue LEDs to form TJs using SAG. TJ µLEDs with squared mesa ranging from 10×10 to 100×100 µm2 were fabricated. The forward voltage (Vf) in the reference TJ µLEDs without SAG is very high and decreases linearly from 4.6 to 3.7 V at 20 A/cm2 with reduction in area from 10000 to 100 µm2, which is caused by the lateral out diffusion of hydrogen through sidewall. By contrast, the Vf at 20 A/cm2 in the TJ µLEDs utilizing SAG is significantly reduced to be 3.24 to 3.31 V. Moreover, the Vf in the SAG TJ µLEDs is independent on sizes, suggesting that the hydrogen is effectively removed through the holes on top of the p-GaN surface by SAG. The output power of SAG TJ µLEDs is ∼10% higher than the common µLEDs with indium tin oxide (ITO) contact.

URLhttp://www.opticsexpress.org/abstract.cfm?URI=oe-28-13-18707
DOI10.1364/OE.394664