2D-SnSe2 nanoflakes on paper with 1D-NiO gate insulator based MISFET as multifunctional NIR photo switch and flexible temperature sensor

In this work, we report a simple, low cost, facile fabrication of a SnSe2 based high mobility Metal-Insulator-Semiconductor-Field-effect-transistor (MISFET) using an unconventional Mott-insulator NiO as gate dielectric for an all-paper-based multifunctional-photoswitch and temperature sensor. A single-step hydrothermal method yielded SnSe2 on cellulose paper while NiO nanofibers, synthesized using Electrospinning technique was used as gate dielectric. Cu-metal tape was used as source, drain and gate contacts while NiO and SnSe2 were used as insulator and semiconductor respectively to fabricate the MISFET. Detailed characterization studies revealed the formation of SnSe2 nanoflakes and NiO nanofibers. The transfer characteristics of SnSe2/NiO FET exhibited a transconductance of 3.25 mu S and mobility of 20 cm(2) V(-1)s(-1) with a Ion/Ioff ratio10(2) which are extraordinary considering the simplicity of the cleanroom free-fabrication technique adopted. The SnSe2 /NiO based FET was used as a NIR-photo-switch and a flexible-temperature sensor. The flexible SnSe2 based NIR-photoswitch demonstrated a responsivity of 28 mA/cm(2), detectivity of 5.25 x 10(6) jones. The FET-based temperature sensor exhibited a TCR value of - 4.3 x 10(-3) degrees C-1, better than many commercially available temperature-sensors. The higher responsivity can be attributed the effective photo-generated carriers and the higher TCR can be imputed to the thermally excited electrons of uniformly grown hexagonal SnSe2 nanoflakes. The fabrication technique of a paper-based FET outlined here is a step ahead in developing 2D materials based low cost, flexible multi-functional electronic-devices.