Intense photoluminescence from highly stacked quantum dash structure fabricated by strain-compensation technique

We fabricated stacks of self-assembled InAs quantum dashes (QDashes) on InP(0 0 1) substrates using a new strain-compensation technique that suppresses degradation of crystal and optical properties by a large stacking number. A 30-layer stacked sample showed that the QDash structure and size uniformity were improved compared with those of a two-layer stacked sample. A stronger 1.5-μm photoluminescence emission was observed in the 30-layer stacked sample at room temperature, and this emission level is suitable for fiber-optic communication systems. In addition, optical anisotropy was observed in these samples.