AFM and SEM Study on Crystallographic and Topographical Evolutions of Wet-Etched Patterned Sapphire Substrate (PSS): Part II. Cone-Shaped PSS Etched in H<sub>2</sub>SO<sub>4</sub>and H<sub>3</sub>PO<sub>4</sub>Mixture with Varying Volume Ratio at 230°C
ECS journal of solid state science and technology