THz emission from Ge/Si nanoostructure

摘要

We report both the electrical and emission measurement on novel structure of Ge/Siquantum dots. Strong radiation is observed in the terahertz (THz) ranging between 60to 140 mm. Theoretical modeling on the energy level of the islands, taking intoaccount of Ge/Si intermixing and strain relaxation, was performed. It shows that, theenergy separation of confined levels of heavy-light holes band are smaller than theoptical phonon energy for a strain less then 20±10%. From the analysis, we concludethat the observed emission was originated from the islands.