Regensburg 2022 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 30: Poster 2

HL 30.12: Poster

Donnerstag, 8. September 2022, 11:00–13:00, P3

Impact of GaN barrier thickness on indium incorporation in GaInN/GaN multiple quantum wells grown via MBE — •Farouk Aljasem, Heiko Bremers, Uwe Rossow Rossow, and Andreas Hangleiter — Institut für Angewandte Physik & Laboratory for Emerging Nanometrology, Technische Universität Braunschweig, Germany

The internal quantum efficiency (IQE) of optical devices based on GaInN is highly sensitive to the thickness of GaInN quantum well. The main way to increase the emission wavelength of GaInN quantum wells is to increase the indium content in the quantum well by enhancing the incorporation rate of indium. We grew fivefold GaInN MQWs at a substrate temperature of 580°C and the GaN barrier layer was grown in two steps. The first step is at the same growth temperature of GaInN quantum wells (580°C), called the low-temperature GaN (LT-GaN) layer and the second step is the high-temperature GaN (HT-GaN), which was grown after the ramping of the substrate temperature up to 725°C. From high-resolution XRD and high-resolution TEM measurements, we found that the thickness of the GaInN wells increased significantly with the increase of the growth time of the LT-GaN layer. The effects of changing the growth time of the LT-GaN layer include changing the indium content of the GaInN well and the thickness of the barrier layer. The analysis of GaInN/GaN MQWs samples using different characterization methods such as HR-XRD, HR-TEM, AFM, and PL provides a detailed understanding of the role of the indium adlayer and its impact on the growth mechanism at low temperatures.