DFT Studies of Organic-2D Material Heterostructures for Optoelectronic Devices

Abstract

2D nano materials have received a lot of attention in recent years due to their physical, chemical, electronic, and optical properties. After the discovery of graphene, more research is underway to understand the basics of these 2D materials. Because of their outstanding stability in the ambient conditions, they have become very popular in the research community. 2D materials such as monolayer MoS2 exhibit wide band gap and low carrier mobility in comparison to graphene. Such electrical and optical properties are hurdle on their use, especially in photo detectors. Therefore, some work needs to be done to improve them electrical and optical properties. Heterostructures of 2D materials have helped greatly in band gap engineering. However, due to the requirements of lattice matching in order to from a heterostructure between two 2D-layers, available combinations and possibilities become limited. Organic molecules readily form heterostructure with 2D materials and there is no limitation of lattice matching, there for making them ideal for future electronic devices. A lot of work has been done showing the formation of 2D structures of organic materials and 2D materials with exceptional qualities such as interlayer charge transfer and formation of exciton which are of critical importance in opto-electronic devices [1]. However, the mechanism and underlying physics is still not well understood. To improve their electronic structure, we must have a deeper understanding at the atomic level. DFT helps us to study the electronic properties such as band structure and density of states. It also provides an in-depth understanding of the electronic behavior of 2D objects with planer symmetry. In this study heterostructures of MoS2 with organic materials such as ZnPc, CuPc and pentacene will be studied using DFT. The Main goal of the study is to propose new organic material as a suitable candidate for optoelectronic devices. To investigate the electrical and physical properties of organic-2D materials, DFT calculations will be performed using the Atomistic Tool kit (ATK). The result will help guide future experimental work for optoelectronic devices [2].