Gate tunable conductivity of hybrid gold nanocrystal–semiconducting matrix thin films

Abstract

The development of hybrid materials from chemically synthesized building blocks offers a unique opportunity to combine on nanoscale various electronic, magnetic, optical and biochemical functionalities that cannot be found in homogenous single materials. One scheme to obtain such composite materials is to embed nanocrystals into thin film field-effect transistors to provide them functionalities not usually found in simple semiconducting materials. To that end, we report on the preparation of Au nanoparticle–metal chalcogenide semiconducting thin films, based on the metal chalcogenide complex Sn₂S₆⁴⁻. This complex has unique complementary properties: on the one hand, it can be used as a precursor for the preparation of all-inorganic thin film transistors; on the other hand, it can be used as a ligand molecule for the colloid stabilization of various types of nanocrystals. After the preparation of chalcogenide stabilized Au nanoparticles, we prepared SnS₂ thin film transistors with increasing concentration of Au nanoparticles. We measured the current–voltage characteristics of these transistors as well as their optical properties by ellipsometric measurements as a function of the nanocrystal concentration. We find that the field effects associated with the transistor properties remain up to a large concentration of nanocrystals impregnated into the semi-conducting film. This shows that the method provides a possible route for the preparation of hybrid semi-conducting-metal nanoparticle transistors, thus, providing a path for the fabrication of a variety of thin-film-based devices (magnetoresistive, electroactive).