A van der Waals p–n Heterojunction Based on Polymer-2D Layered MoS₂ for Solution Processable Electronics

Abstract

Organic–inorganic heterostructures are emerging materials for developing high performance, solution processable organic electronic and optoelectronic devices. In particular, the heterostructures of semiconducting two-dimensional (2D) transition metal dichalcogenides (TMDs) are interesting due to the quantum confinement effect, extended solar light absorption, and tunable optoelectronic properties. Here, we report a facile and fully solution processable method called semiconductive polymer assisted chemical exfoliation (SPACE) of synthesizing polymer-MoS 2 nanoheterostructures. Synthesized polymer grafted MoS 2 (PG-MoS 2 ) nanoheterostructures consist of a few layers of MoS 2 and are chemically quite stable. The phase integrity of MoS 2 in PG-MoS 2 is confirmed by various microscopic and spectroscopic techniques. Efficient dissociation of excitons in PG-MoS 2 heterostructures is reported and explained based on electron and hole transfers. Strong photovoltaic effects are observed in the polymer-MoS 2 heterojunction devices due to photocarrier generation at the interface. In addition, we demonstrate a bipolar resistive switching effect with very high ON/OFF ratio (∼10 4 ) in a PG-MoS 2 sandwiched device. A thorough carrier transport study has been undertaken to understand the switching effect. Our results reveal that the heterostructures of polymer and layered TMDs could be the basis for up-and-coming solution processable solar cells and memory devices.