ABSTRACT
Absorption, photocurrent, and far-infrared reflectivity spectra of the polycrystalline β-FeSi2 thin films in relation with the Si substrate temperature are presented. The photocurrent spectra related with the fundamental interband, extrinsic defect transitions of β-FeSi2 and the intrinsic transitions of Si substrates are observed. Both the absorption and photocurrent measurements show the direct gap characteristics. A simple recombination model is proposed to account for the photocurrent results. We show that β-FeSi2 films with better quality can be achieved at higher substrate temperature during growth. The simplicity, sensitivity and reliability of the photocurrent measurements for studying β-FeSi2 are well demonstrated.
