Properties of GaN-based light-emitting diodes on patterned sapphire substrate coated with silver nanoparticles prepared by mask-free chemical etching
Department of Electro-optical Engineering, National Taipei University of Technology, 1, Sec. 3, Chung-Hsiao E. Rd, Taipei 106, Taiwan
Nanoscale Research Letters 2013, 8:157 doi:10.1186/1556-276X-8-157Published: 8 April 2013
This study reports on the use of a template that is made of silver nanoparticles (ANPs) that are dispersed on a patterned sapphire substrate (PSS) to improve the light output power of GaN-based light-emitting diodes (LEDs). The dipping of a sapphire substrate in hot H2SO4 solution generates white reaction products that are identified as a mixture of polycrystalline aluminum sulfates. These white reaction products can act as a natural etching mask in the preparation of an ANP-coated PSS (PSS-ANP) template. The optimal annealing temperature and time, surface morphology, and optical characteristics of the PSS-ANP template were investigated. The light output power of an LED that is bonded to the PSS-ANP template is approximately double than that of an LED that is not.