Silicon-based two-dimensional chalcogenide of p-type semiconducting silicon telluride nanosheets for ultrahigh sensitive photodetector applications

Abstract

Two-dimensional (2D) materials have attracted significant attention in recent years owing to their exotic properties. Semiconducting p-type 2D crystals are crucial to the construction of versatile p–n junction-based nanoelectronic devices, and promising future optoelectronic applications. Herein, we reported the growth of high-quality p-type silicon telluride (Si₂Te₃) single crystals using the chemical vapor transport (CVT) technique. Few layered Si₂Te₃ nanosheets were obtained by mechanical exfoliation and used to fabricate a phototransistor device under a rigid silicon substrate. The Si₂Te₃ nanosheet-based transistor exhibits an outstanding device performance, such as a high photoresponsivity of approximately 1396 A W⁻¹ and a larger specific detectivity of approximately 2.52 × 10¹² Jones at a wavelength of 633 nm. The values obtained using the Si₂Te₃ single crystal are remarkably superior to those obtained for the other chalcogenide 2D crystals, such as Bi₂Te₃ and Sb₂T_e3. In addition, the normalized gain value of approximately 2.74 × 10⁻⁴ V⁻¹ cm² achieved using this field-effect transistor (FET) device is several orders higher than those of the other 2D single crystal-based FET devices. Our results suggest that the Si₂Te₃ single crystal could be a benchmark candidate for the integration of prospective p–n junction circuits and photo-sensing applications.