Effect of substrate misorientation on the InAs/InAlAs/InP nanostructure morphology and lateral composition modulation in the InAlAs matrix

Abstract

The authors report the self-organized growth of InAs∕InAlAsquantum wires on nominal (001) InP substrate and (001) InP substrates misoriented by 2°, 4°, and 8° towards both [−110] and [110]. The influence of substrate misorientation on the structural and optical properties of these InAs∕InAlAsquantum wires is studied by transmission electron microscopy and photoluminescence measurements. Compared with that grown on nominal (001) InP substrate, the density of InAs∕InAlAsquantum wires grown on misoriented InP(001) substrates is enhanced. A strong lateral composition modulation effect take place in the InAlAs buffer layers grown on misoriented InP substrates with large off-cut angles (4° and 8°), which induces a nucleation template for the first-period InAsquantum wires and greatly improve the size distribution of InAsquantum wires.InAs∕InAlAsquantum wires grown on InP (001) substrate 8° off cut towards [−110] show the best size homogeneity and photoluminescence intensity.