Highly conductive and long-term stable films from liquid-phase exfoliated platinum diselenide

Liquid-phase exfoliation (LPE) has been introduced as a versatile and scalable production method for two-dimensional (2D) materials. This method yields dispersions that allow for the fabrication of printable and flexible electronic devices. However, the fabrication of uniform and homogeneous films from LPE dispersions with a performance similar to that of bottom-up grown materials remains a challenge, as the film quality strongly influences the optical and electrical performance of devices. Furthermore, long-term stability remains a major challenge for all 2D material based applications. In this study, we report on highly conductive tiled network films made of platinum diselenide (PtSe2) flakes derived using a scalable LPE method. We characterized the homogeneous films in terms of morphology and electrical behavior. As an example of applicability, we produce a chemiresistive sensor structure with the PtSe2 films and show significant resistance changes upon periodic ammonia gas exposures, revealing a sub-0.1 part per million (ppm) detection limit (DL). More remarkably the devices are fully functional after 15 months, underlining the high stability of PtSe2 based devices.

Automated summary

Liquid-phase exfoliation (LPE) is a versatile and scalable method for producing two-dimensional (2D) materials. In this study, highly conductive films made of platinum diselenide (PtSe2) flakes were successfully fabricated using LPE. These films showed uniform morphology and electrical behavior, and were used to create a chemiresistive sensor structure capable of detecting ammonia gas at sub-0.1 parts per million (ppm) levels. Remarkably, the PtSe2-based devices remained fully functional even after 15 months, demonstrating their high stability.