Highly sensitive and fast phototransistor based on large size CVD-grown SnS2 nanosheets

Abstract

A facile and fruitful CVD method is reported for the first time, to synthesize high-quality hexagonal SnS₂ nanosheets on carbon cloth via in situ sulfurization of SnO₂. Moreover, highly sensitive phototransistors based on SnS₂ with an on/off ratio surpassing 10⁶ under ambient conditions and a rising time as short as 22 ms under vacuum are fabricated, which are superior than most phototransistors based on LMDs. Electrical transport measurements at varied temperatures together with theoretical calculations verify that sulfur vacancies generated by the growth process would induce a defect level near the bottom of the conduction band, which significantly affects the performance of the SnS₂ device. These findings may open up a new pathway for the synthesis of LMDs, shed light on the effects of defects on devices and expand the building blocks for high performance optoelectronic devices.