Regensburg 2019 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 31: Nitrides: Preparation and characterization II
HL 31.7: Vortrag
Mittwoch, 3. April 2019, 16:45–17:00, H31
Nanoscale structural and optical properties of deep UV-emitting GaN/AlN quantum well stack — •Bowen Sheng1,2, Yixin Wang1, Xin Rong1, Zhaoying Chen1, Tao Wang1, Ping Wang1, Gordon Schmidt2, Frank Bertram2, Peter Veit2, Jürgen Bläsing2, Hideto Miyake3, Hongwei Li4, Shiping Guo4, Zhixin Qin1, Andre Strittmatter2, Jürgen Christen2, Bo Shen1, and Xinqiang Wang1 — 1School of Physics, Peking University, Beijing, China — 2Institute of Physics, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany — 3Department of Electrical and Electronic Engineering, Mie University, Mie, Japan — 4Advanced Micro-Fabrication Equipment Inc., Shanghai, China
We successfully have grown 100 periods of GaN/AlN MQWs with monolayer-thick GaN quantum well on high-quality thermally annealed AlN template by MOCVD. The thickness of AlN barriers is nominally 10 nm. The STEM image contrast is evidencing that the GaN quantum wells are nicely embedded in AlN matrix with sharp interfaces and monolayer thickness of the GaN QWs. A cross-sectional CL linescan performed at 17 K overall reveals the emission evolution: at the beginning of GaN MQWs, the emission has a slight redshift from 225 to 230 nm, then stays perfectly constant towards the top surface. Finally, under higher magnification, the panchromatic CL map resolves the first 13 QW pairs. The CL intensity modulation matches perfect with HAADF contrast. Under this high spatial resolution we are able to resolve the distance between two quantum wells determined as 10.8 nm, not only in HAADF but also in CL intensity.