Hirotatsu Ishii

Fine-structure N-polarity InN∕InGaN multiple quantum wells grown on GaN underlayer by molecular-beam epitaxy

We have succeeded in the growth of very-fine-structure InN∕InGaN (3–16nm∕9nm) multi-quantum wells (MQWs) on GaN underlayer and characterized them by transmission electron microscopy (TEM), high-resolution x-ray diffraction (XRD), and photoluminescence (PL) at 13K. Clear satellite diffraction peaks and sharp heterointerfaces were observed by XRD and TEM, respectively. A single PL-emission peak at 1.75μm was observed in the ten-periods InN(16.1nm)∕In0.67Ga0.33N(9.2nm) MQWs. The use of the InGaN as a barrier layer instead of GaN resulted in remarkable reduction of lattice mismatch between the well and barrier, which was essential for the fabrication of MQWs with superior interface quality. This successful growth of fine-structure InN∕InGaN MQWs would be an important step for the application of InN in optical communication devices.