Effect of Template–Mediated Alumina Nanoparticle Morphology on Sapphire Wafer Production via Heat Exchange Method

The sapphire crystal, the most commonly used LED substrate material, has excellent optical and chemical properties and has rapidly developed in recent years. However, the challenge of growing large–size sapphire crystals remains. This paper presents a novel approach using alumina nanoparticles synthesized with abietic acid as a template to enhance sapphire growth via the heat exchange method. This study explores the effects of temperature, time, and template amount on the structure and morphology of the synthesized alumina nanoparticles. The results show that the morphology of the raw material, particularly spherical alumina nanoparticles, positively affects the quality and yield stability of sapphire products. Furthermore, the light output power of GaN–based LED chips made with the experimentally fabricated sapphire substrate increased from 3.47 W/µm(2) to 3.71 W/µm(2), a 6.9% increase compared to commercially available sapphire substrates. This research highlights the potential of using abietic acid as a template for alumina nanoparticle synthesis and their application in sapphire growth for LED production.