Hassan Melhem

PhD Student

I graduated from the university of Montpellier with a master’s degree in fundamental physics & Nanoscience. I am currently doing a PhD in C2N in SEEDs team on the epitaxial growth of the allotropic phase of the SiGe-2H by UHV CVD. SiGe-alloys with their standard diamond cubic phase are all indirect bandgap semiconductors. Their inability to efficiently emit light has adversely shaped the semiconductor industry we know today. Playing on crystal polytypism is an efficient way to change material properties and especially modify the band structure. Hexagonal crystal phase SiGe (Hex-SiGe) and particularly Ge-2H recently emerged as a new direct bandgap (0.3 eV) semiconductor with excellent light emission capabilities in MIR.

Figures : left) GaAs wurzite nanowire, middle) GaAs wurzite /Ge-2H nanowire, right) TEM Ge-2H on GaAs-w

Publications