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

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 (Si 2 Te 3 ) single crystals using the chemical vapor transport (CVT) technique. Few layered Si 2 Te 3 nanosheets were obtained by mechanical exfoliation and used to fabricate a phototransistor device under a rigid silicon substrate. The Si 2 Te 3 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 × 10 12 Jones at a wavelength of 633 nm. The values obtained using the Si 2 Te 3 single crystal are remarkably superior to those obtained for the other chalcogenide 2D crystals, such as Bi 2 Te 3 and Sb 2 T e3 . In addition, the normalized gain value of approximately 2.74 × 10 −4 V −1 cm 2 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 Si 2 Te 3 single crystal could be a benchmark candidate for the integration of prospective p-n junction circuits and photo-sensing applications. We demonstrate an outstanding visible light photodetector fabricated with high-quality 2D silicon telluride single crystal grown by chemical vapor transport technique.