Highly Sensitive Pyroelectric Detector Using Atomically Thin Nanoscale Silicon Ditelluride

Abstract

Two-dimensional (2D) materials are increasingly being used as detectors and are gaining popularity due to the advantage of tunability of their electrical and thermal properties. Certain non-centrosymmetric materials exhibit a property known as pyroelectricity, which can be utilized to detect infrared (IR) radiation. On the other hand, the pyroelectric effect can be induced in centrosymmetric materials by making them react to external stimuli that break up their symmetry. Here, we report the pyroelectric behavior of a centrosymmetric 2D SiTe2 by inducing interface polarization in a Schottky junction. For this bulk, SiTe2 was synthesized via induction melting and its 2D counterpart via liquid-phase exfoliation. A pyroelectric photodetector in Au/p-SiTe2/ITO configuration was fabricated. The electrical studies confirm the formation of a Schottky junction. The 2D SiTe2-based pyroelectric detector exhibited a high pyroelectric coefficient of 3.73 mC/m2 K and a good responsivity of 3.9 × 105 Jones. The obtained pyroelectric coefficient using 2D SiTe2 was remarkably superior to that of conventional bulk materials. This enhanced property arises from the combined effect of the two-dimensional nature of the material and the induced interface polarization in the device. We employed density functional theory to support our experimental observations. The performance results suggest that 2D SiTe2 could be a benchmark candidate for ultrafast pyroelectric detectors.