Annealing effects and infrared photoelectric response of β-FeSi2 on Si (100) substrate prepared by pulsed laser deposition

Abstract

β-FeSi2 is known as an important semiconducting silicide in the field of optoelectronics. In this paper, β-FeSi2 alloy layers were prepared on Si (100) substrates by deposition of Fe thin films with pulsed laser deposition, followed by thermal annealing in vacuum at a temperature of 800 °C. The adjustment of the annealing temperature had obvious effects on the morphology, structure and optical properties of the samples. The 800 °C-annealed sample exhibits a smooth surface and has a β-FeSi2 phase with a good structure. By using the prepared β-FeSi2 alloy layer as the photoelectric conversion layer, an infrared detector was fabricated with a responsivity of 1.8 mA/W and detectivity of 1.44 × 107 cm⋅Hz1/2⋅W−1 at 1319-nm wavelength.