Fast-Response Amorphous In₂Te₃ Short-Wave Infrared (SWIR) Photodetector

Abstract

Despite the wide applications of Short-Wave Infrared (SWIR) imaging, standard imaging materials require lattice matching and complex fabrication techniques which are relatively expensive. In this work, 50 nm thick amorphous indium telluride (In2Te3) films are RF sputtered on a silicon substrate at 300 C. The films are used to fabricate back-gated field-effect photodetectors (PDs). The In2Te3 detectors exhibit a broad wavelength response from 406 nm to 1600 nm and a photo responsivity of 0.44 AW -1 under 1310 nm excitation at 5 V bias. Furthermore, an n-type behavior with an electron field-effect mobility of 1.15 cm 2 V -1 s -1 is observed. We also evaluated the frequency response of the PDs under 1310 nm modulated light, a 3dB cut-off frequency of ~0.97 MHz is measured. Further, the device exhibits specific detectivity of the 1.32 x 10 9 Jones and very good stability at ambient conditions.