An effective approach to realize graphene based p-n junctions via adsorption of donor and acceptor molecules

摘要

Atomically thin two dimensional materials such as graphene offer excellent capabilities suitable for a number of low power versatile applications. Here, employing first principle calculations, we introduce a feasible approach to realize an efficient graphene based p-n junction (PNJ) which is composed of non-covalently physisorbed tetracyanoquinodimethane (TCNQ) and tetrathiafulvalene (TTF) molecules onto an armchair graphene nanoribbon (AGNR). We show that compared to conventional graphene based p-n systems, our suggested PNJ exhibits low threshold voltage (Vth), large current-voltage ratio, and almost no sensitivity to conformational variations. Using a simple model, we also provide a theoretical background to explain the rectifying behavior of the suggested PNJ and show that tuning the distance between p and n doped regions modifies the current-voltage ratio. Our study indicates that the perfect diode behavior along with stability under various practical conditions makes our proposed PNJ a promising building block to fabricate next generation graphene based nanosize transistors. (C) 2019 Elsevier Ltd. All rights reserved.