Search

The development of inkjet-printed 2D crystal inks offers the ability to print different 2D materials on various substrates to form vertical heterostructures. However, the detailed characterization of the atomic structures of the inkjet-printed MoTe2 nanosheets has been rarely reported. In this work, water-based 2D crystal inks of MoTe2, WS2, and graphene have been prepared and printed to obtain the flexible photodetectors. The absorption coefficient of MoTe2 has been estimated as α (500 nm) = 925 ± 47 lg−1 m−1 using the gravimetric method. Intriguingly, the inkjet-printed MoTe2 nanosheets down to 4 nm show both the semiconducting 2H and metallic 1T′ phases. The responsivities of the photodetectors based on MoTe2/graphene and WS2/graphene heterostructures can reach 120 mA/W and 2.5 A/W at 532 nm, respectively. Moreover, the inkjet-printed MoTe2/graphene shows a responsivity of 7.7 mA/W at 940 nm. The fabrication technique of inkjet printing will help design flexible optoelectronic devices based transition metal dichalcogenide–graphene heterostructures for the near-infrared photo detection. [ABSTRACT FROM AUTHOR]