Atomic Layer Deposition and Strain Analysis of Epitaxial GaN-ZnO Core-Shell Nanowires

We demonstrate theepitaxial coating of GaN NWs with an epitaxialZnO shell by atomic layer deposition at 300 & DEG;C. Scanning transmissionelectron microscopy proves a sharp and defect-free coherent interface.The strain in the core-shell structure due to the lattice mismatchand different thermal expansion coefficients of GaN and ZnO was analyzedusing 4D-STEM strain mapping and Raman spectroscopy and compared totheoretical calculations. The results highlight the outstanding advantagesof epitaxial shell growth using atomic layer deposition, e.g., conformalcoating and precise thickness control.

Automated summary

We demonstrate the epitaxial coating of GaN NWs with an epitaxial ZnO shell by atomic layer deposition. Scanning transmission electron microscopy confirms a sharp and defect-free coherent interface. The strain in the core-shell structure was analyzed using 4D-STEM strain mapping and Raman spectroscopy, and compared to theoretical calculations. The results highlight the advantages of epitaxial shell growth using atomic layer deposition, such as conformal coating and precise thickness control.