[MoD4] Advanced LED Technologies

4:30 PM - 5:00 PM JST(7:30 AM - 8:00 AM UTC)

[MoD4-01 Invited] Heteroepitaxy of semiconductors for infrared optoelectronics and understanding dislocation behavior

〇Kunal Mukherjee¹ (1. Stanford University (USA))

We aim to understand the effect of threading dislocations that arise due to heteroepitaxy of narrow bandgap III-V and IV-VI semiconductors on commercially available substrates. We show, aided by new microscopy tools, that GaAs based devices, including near-IR InAs quantum dot lasers grown on silicon, suffer from additional dislocation that arise due to thermal expansion mismatch and dislocation pinning. We devise a filtering scheme to separate these dislocations from the active layer and significantly improve laser reliability. We also revisit IV-VI PbSe and PbSnSe semiconductors by heteroepitaxy on 8%-mismatched GaAs substrates towards LEDs in the 4-8 um range with an aim to harness their low bulk Auger coefficients. We show preliminary work on MBE-grown films showing room temperature luminescence and simple devices, suggesting IV-VI semiconductors are potentially more tolerant of dislocations even in the 10⁹/cm² range.