SnSe2-a layered two-dimensional semiconductor is an naturally earth-abundant and environment-friendly material.  

SnSe2 is very promising in the applications for the next-generation wearable smart device and flexible sensor, owing to the merits of direct band-gap nature, high surface-to-volume ratio and low cost. Given that the large-scale uniform films are the foundation of the integrated electronic/optoelectronic applications in the future, the currently demonstrated methods can only offer limited scale of the SnSe2 films, generally in the form of isolated flakes. These small-scale and isolated SnSe2 flakes have the fundamental difficulties to meet the practical needs in wearable devices.   

Dr. CHEN Ming, working at the Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences (SIAT), together with his co-works demonstrated the large-scale (10 cm × 10 cm), uniform, single crystalline and self-standing SnSe2 nanoplate arrays by co-evaporation processed on flexible polyimide substrates. Furthermore, they explore the applications of the polyimide/SnSe2 nanoplate arrays as wearable gas sensors for detecting methane. The wearable gas sensors show high sensitivity, fast response, recovery and good uniformity .

This work not only provides an efficient technique to obtain large-area, uniform and high-quality single-crystalline SnSe2 nanoplates, but also impacts on the future developments of layered metal dichalcogenides-based wearable devices.

The paper “Large-scale synthesis of single-crystalline self-standing SnSe2 nanoplate arrays for wearable gas sensors” was published on Nanotechnology 2018.

Fig. Large-scale synthesis of single-crystalline self-standing SnSe2 nanoplate arrays for wearable gas sensors