Correlating cathodoluminescence and scanning transmission electron microscopy for InGaN platelet nano-LEDs

• Published in: Applied physics letters Vol. 123; no. 2
• Main Authors: Persson, Axel R., Gustafsson, Anders, Bi, Zhaoxia, Samuelson, Lars, Darakchieva, Vanya, Persson, Per O. Å.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 10.07.2023
• Subjects: Applied physics; Atomic structure; Boundaries; Cathodoluminescence; Condensed Matter Physics (including Material Physics, Nano Physics); Den kondenserade materiens fysik (Här ingår: Materialfysik, nanofysik); Fysik; Indium gallium nitrides; Light emitting diodes; Natural Sciences; Naturvetenskap; Optical properties; Optoelectronic devices; Physical Sciences; Quantum wells; Radiative recombination; Scanning transmission electron microscopy; Semiconductor devices; Stacking
• ISSN: 0003-6951; 1077-3118; 1077-3118
• DOI: 10.1063/5.0150863

Structural defects are detrimental to the efficiency and quality of optoelectronic semiconductor devices. In this work, we study InGaN platelets with a quantum well structure intended for nano-LEDs emitting red light and how their optical properties, measured with cathodoluminescence, relate to the corresponding atomic structure. Through a method of spectroscopy–thinning–imaging, we demonstrate in plan-view how stacking mismatch boundaries intersect the quantum well in a pattern correlated with the observed diminished cathodoluminescence intensity. The results highlight the importance of avoiding stacking mismatch in small LED structures due to the relatively large region of non-radiative recombination caused by the mismatch boundaries.