Locally Gated SnS₂/hBN Thin Film Transistors with a Broadband Photoresponse

Next-generation flexible and transparent electronics demand newer materials with superior characteristics. Tin dichalcogenides, Sn(S,Se)₂, are layered crystal materials that show promise for implementation in flexible electronics and optoelectronics. They have band gap energies that are dependent on their atomic layer number and selenium content. A variety of studies has focused in particular on tin disulfide (SnS₂) channel transistors with conventional silicon substrates. However, the effort of interchanging the gate dielectric by utilizing high-quality hexagonal boron nitride (hBN) still remains. In this work, the hBN coupled SnS₂ thin film transistors are demonstrated with bottom-gated device configuration. The electrical transport characteristics of the SnS₂ channel transistor present a high current on/off ratio, reaching as high as 10⁵ and a ten-fold enhancement in subthreshold swing compared to a high-κ dielectric covered device. We also demonstrate the spectral photoresponsivity from ultraviolet to infrared in a multi-layered SnS₂ phototransistor. The device architecture is suitable to promote diverse studied on flexible and transparent thin film transistors for further applications.