Deep-ultraviolet stimulated emission from AlGaN/AlN multiple-quantum-wells on nano-patterned AlN/sapphire templates with reduced threshold power density

We first report deep-ultraviolet (DUV) stimulated emission by optical pumping of AlGaN/AlN multiple-quantum-wells (MQWs) on nano-patterned AlN/sapphire (NP-AlN/sapphire) templates with significant threshold power density (Pth) reduction. Thanks to nanoscale lateral overgrowth on nano-holes patterns, the full width at half-maximum values of (0002) and (101¯2) X-ray diffraction rocking curves of the NP-AlN/sapphire template are 85 and 338 arcsec, deducing 71% less threading dislocations than the planar AlN/sapphire template. AlGaN/AlN MQWs on the NP-AlN/sapphire template exhibit DUV stimulated emission at 271.9 nm with spectral linewidth of 0.66 nm and Pth of 810 kW/cm2, 68% lower compared to the same MQWs structure on a traditional planar AlN/sapphire template.