Electrical and optical properties improvement of GeSn layers formed at high temperature under well-controlled Sn migration. (1st November 2017) - Taoka, Noriyuki
Abstract: Electrical and optical properties of GeSn layers formed at various growth conditions under changing deposition temperature ( T d ) and deposition speed ( v d ) were systematically investigated. A high Sn content of 3.0% leads to high electron mobility and electron concentration for an as-deposited sample compared with the Sn content of 1.9%. Subsequent annealing at 550 °C after the growth is effective for improving the mobility and the activated carrier concentration. Moreover, the high v d and T d growth makes it possible to get clear photoluminescence (PL) signal from the band-to-band transition of the GeSn layers. The annealing at 550 °C leads to the high and sharp PL spectra compared with those for the as-deposited samples. Consequently, we found that the high v d and T d growth of the GeSn layers suppressing the Sn migration is quite important for getting electrical and optical properties to realize future electrical and optical devices.