Improved crystalline quality and light output power of GaN‐based light‐emitting diodes grown on Si substrate by buffer optimization

Abstract

AbstractHigh‐quality crack‐free GaN‐based light‐emitting diodes (LEDs) were grown on patterned Si substrate using a flow modulation method and a high‐temperature (HT)‐AlN/AlGaN superlattice structure (SLs) interlayer. The effects of these two techniques on material properties and device performance were studied. The enhanced crystalline quality can be attributed to a 3D to 2D coalescence process with fewer dislocations initiated from the interlayers. The light output power of blue LEDs was improved by 66% after successful implementation of flow modulation and new interlayers. After substrate removal and packaging, the optical power of circle LEDs with diameter of 300 μm could reach as high as 6.30 mW at 20 mA. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)