Fabrication and Investigation of InSb Thin Films for IR SAW Photodetectors

Abstract

The two-stage pulsed laser deposition growth of thin InSb films on (111) Si and on LiNbO₃ YX-128° substrates was studied using a thin InSb buffer layer deposited at a low temperature. This approach improves carrier mobility in InSb base layer, which largely determines the sensitivity of IR photodetectors at room temperature. The response speed in the near-IR range at λ = 985 nm was 1.92 ms, and the decay time was 1.67 ms, under xenon lamp radiation with mechanical modulation. The photosensitivity of the InSb/(111) Si film was about 1 A/W at 293 K. The response time of the sample was~6.8 μs, the time of complete recovery was ~34.5 μs, under laser diode radiation with a wavelength of 840 nm, power 1 mW.