Photoluminescence properties of polycrystalline beta-FeSi2 grown by RF magnetron sputtering

Photoluminescence (PL) properties of beta-FeSi2 polycrystalline thin films and Si/beta-FeSi2/Si doublehetero (DH) structure samples grown by an RF magnetron sputtering method were investigated. In the thin films, the PL intensity at 1.54 mu m was increased in B-doped beta-FeSi2 films. In the Si/B-doped beta-FeSi2/Si DH samples, the PL intensity became much larger than the B-doped thin films. In the dependence of PL intensity on beta-FeSi2-thickness, the PL intensity strongly depended on the beta-FeSi2 thickness and showed a maximum at 2.5 nm. In the measurements of PL lifetime, the PL lifetimes were constant in the DH samples with different thickness of beta-FeSi2. These results showed that the confinement of photoexcited carriers in the beta-FeSi2 layer decreased as the beta-FeSi2 thickness increased. (c) 2020 The Japan Society of Applied Physics