We report the growth of high crystalline quality GaN-based light emitting diodes (LEDs) on Si (111) substrates with AlN/GaN superlattice interlayer for both stress and dislocation engineering. A focused study involved comparison of different interlayer structures including low-temperature AlN, medium-temperature AlN multilayers and AlN/GaN supperlattice for optimization of the LED performance. The results show that the AlN/GaN supperlattice interlayer is the most effective in reducing the residual tensile stress and improving the crystalline quality of GaN on Si. With the AlN/GaN superlattice interlayer, optical properties of the LEDs were enhanced and optical output power of unpackaged LED chips on Si substrates was improved by 24%. (C) 2012 Elsevier B.V. All rights reserved.