2‑inch AlN on Patterned Sapphire Substrate (PSS) Epitaxial Wafer is a high‑quality undoped AlN thin‑film grown epitaxially on micro‑patterned C‑plane sapphire substrate. The patterned structure effectively reduces threading dislocation density, enhances light extraction efficiency and improves crystal quality of subsequent AlGaN/GaN epitaxy. Featuring wide band‑gap, excellent deep‑ultraviolet transmittance, high thermal conductivity and epi‑ready surface, this wafer is well‑suited for high‑brightness UV‑LED, DUV optoelectronic devices, nitride‑based laser diodes and semiconductor research. Custom specifications including PSS pattern shape, pattern pitch, AlN film thickness and cleaning grade are available upon request.