AlInN/GaN superlattice properties under varying gas flows

The properties of Al 1-x In x N/GaN superlattices (SLs) grown by metalorganic chemical vapor deposition at varying gas flows are characterized. Two sets are grown, the first by varying the (TMIn)/(TMIn + TMAl) gas-phase ratio (GPR) and the second by varying the Trimethylindium (TMIn) and Trimethylaluminum (TMAl) flow rates at a fixed GPR. AFM revealed an atomically smooth surface with well-defined atomic terraces and monolayer steps with root-mean-square roughness values as low as 0.229 nm, confirming two-dimensional step-flow growth. Indium content ranges from x = 0.06 to 0.22 and increases with increasing (TMIn)/(TMIn + TMAl) and flow rates across varying growth temperatures. Higher GPRs and flow rates enable higher growth temperatures, resulting in fewer nonradiative defects and room-temperature photoluminescence at 3.95 eV from the GaN quantum wells within the SLs. SL results demonstrate a wide range of advantageous properties useful in optoelectronic materials and devices.