Fabrication of nano-cavity patterned sapphire substrate using self-assembly meshed Pt thin film on c-plane sapphire substrate

In this work, a nano-cavity patterned sapphire substrate (nc-PSS) is fabricated by using a self-formed meshed Pt thin film on a c-plane sapphire substrate. The light output power of a GaN-based light emitting diode on the nc-PSS is 45% greater than that of a control light emitting diode that was prepared on a flat c-plane sapphire substrate (f-SS) wafer. The GaN-based light emitting diode that was prepared on the nc-PSS exhibited much less drooping than a GaN-based light-emitting diode that was prepared on a commercial semi-sphere patterned sapphire substrate (r-PSS), mainly because the voids that formed at the cavities at the GaN/nc-PSS interface buffered the stress in the GaN epi-layers that was imposed by the sapphire substrate.