Title | Metalorganic chemical vapor deposition-grown tunnel junctions for low forward voltage InGaN light-emitting diodes: epitaxy optimization and light extraction simulation |
Publication Type | Journal Article |
Year of Publication | 2021 |
Authors | Li, P., H. Li, H. Zhang, M. Iza, J. S. Speck, S. Nakamura, and S. P. DenBaars |
Journal | Semiconductor Science and Technology |
Volume | 36 |
Pagination | 035019 |
Date Published | 02/2021 |
Abstract | In this work, we demonstrate the detailed optimization of metalorganic chemical vapor deposition (MOCVD)-grown tunnel junctions (TJs) utilizing selective area growth (SAG) for regular size (0.1 mm2) and micro-size InGaN light-emitting diodes (LEDs and µLEDs). Finite-difference time-domain simulations show that the SAG apertures result in a more directional light emission of far-field radiation pattern for the SAG TJ LEDs grown on patterned sapphire substrate. Moreover, it is noted that the n-InGaN insertion layer and Si-doped concentration in the n+GaN TJs layer is essential to realize a low forward voltage (V f) in TJs LEDs. For both 0.1 mm2 LEDs and µLEDs, the V f is independent on the SAG aperture space varied from 3 to 8 µm when the Si-doping level in the n+GaN layer is as high as 1.7 × 1020 cm−3. The optimized TJ LEDs exhibit a comparable differential resistance of 1.0 × 10−2 Ω cm2 at 100 A cm−2 and a very small voltage penalty of 0.2–0.3 V compared to the conventional indium tin oxide contact LEDs. The low V f penalty is caused by a higher turn on voltage, which is the smallest one among the MOCVD-grown TJs LEDs and comparable to the best molecular beam epitaxy-grown TJs LEDs. |
URL | https://doi.org/10.1088/1361-6641/abe0f7 |
DOI | 10.1088/1361-6641/abe0f7 |