Photoelectric study of β-FeSi2 on silicon: Optical threshold as a function of temperature

Publisher Website
Google Scholar
Abstract
Investigation of the photoelectric properties of several metal/β‐FeSi2/Si heterostructures is presented. For thin silicide samples (200 Å), the photocurrent follows a Fowler’s law with a threshold Φ1 lower than the silicide band gap Eg. For thicker silicide samples (2500 Å), the behavior of the photocurrent is different because the optical absorption within the silicide can no longer be neglected: a maximum of the photocurrent is observed instead at Eg. The variations of Eg and Φ1 with temperature are compellingly similar and show the strong effect of the electron‐phonon coupling. We suggest that the threshold Φ1 corresponds to transitions between a trap localized near the heterojunction and the silicide conduction band.