InGaN/GaN light-emitting diodes on Si(1 1 0) substrates grown by metal-organic vapour phase epitaxy

We report on the implementation of InGaN/GaN-based light-emitting diodes (LEDs) structures on Si(1 1 0) oriented substrates grown by metal-organic vapour phase epitaxy. The total thickness of the completely crack-free device structures on Si(1 1 0) substrates amounts to 2.5 μm exhibiting a comparable or even better layer quality than identical LED structures grown on standard Si(1 1 1) substrates. This result can be explained by a more suited epitaxial relation between the c-plane of the high-temperature AlN seed layer and the Si(1 1 0) surface. The crystallographic structure of the LEDs was analysed by x-ray diffraction and the optical properties were investigated by photo- and electroluminescence. The improved crystallographic quality on Si(1 1 0) goes in line with a higher peak intensity in the photoluminescence measurements. Furthermore, a bright bluish light emission at 490 nm is obtained by an electrical excitation at room temperature.