The scientific research on application of graphene in optoelectronics is mainly focused on designing and building hybrid systems aim to increase electrical conductivity and modification of work function of graphene. It can helps to design a new type of conducting and transparent electrodes with the ability of energy level alignment in optoelectronics systems. Even though the interest of hybrid systems increases rapidly, the physical phenomena responsible for their properties are still not fully understood. The aim of this project is developing, creating and modifying graphene-transition metal oxide (TMO) MoO3, ReO3, TiO2 hybrid systems and investigating how their structure influences graphene doping processes, the charge carrier injection, transport and light emission processes when they are incorporated as transparent electrodes in organic light emitting diode (OLED) structures. Based on experimental and theoretical (DFT, TB) studies we are going consider graphene/TMO/molecule interfaces with weak and moderate interactions between molecules and hybrids. This can help us check the efficiency of ICT (integer charge-transfer) and IDIS (induced-density-interface-states) models to describe the energy level alignment of such organic systems. To the best of our knowledge such studies have not been conducted yet. The novelty of our project is also application and investigations of graphene hybrids as a hole and electron injection layers (HIL/EIL) in OLED structure. In the course of the project we will address several scientific hypothesis, however the most important is: based on experimental and theoretical studies it is possible to design model of graphene/TMO/molecular layer junction for OLED application.

Results of the planned research will have a significant impact on development of new materials for optoelectronics, spintronics and photonics. Learning the basic nature of phenomena related to charge carrier transport in organic-inorganic hybrid structures will allow to answer key issues in interlayer interactions. Furthermore, it will allow for intentional, controlled development of new class of multilayered materials, in which 2D materials – graphene will be integrated with thin transition metal oxide layers. Analysis of an influence of modifications of electronic structure of hybrid system on effectiveness of charge carrier injection into organic layer will be conducted. It will be a significant contribution into learning the processes behind the effectiveness of photoemission in OLEDs. In future the analyses developed in course of this project can serve as a base for further, applied studies, in particular ones related to principles of operation and effectiveness of new generation of OLED and organic photovoltaic (OPV) systems. In further perspective the results of this project will contribute to development of new technologies oriented towards effective acquisition and saving of electric power.