| AVS 61st International Symposium & Exhibition | |
| Electronic Materials and Processing | Wednesday Sessions |
| Session EM-WeA |
| Session: | High-K Dielectrics for 2D Semiconductor |
| Presenter: | Pabitra Choudhury, New Mexico Institute of Mining and Technology |
| Authors: | P. Choudhury, New Mexico Institute of Mining and Technology A.C. Kummel, University of California at San Diego |
| Correspondent: | Click to Email |
Metal phthalocyanine (MPc) molecules are composed of a metal atom and a surrounding pthalocyanine ligand ring. The metal-ligand interaction and molecule-surface interaction are the two most important parameters, which controls the various physical and chemical properties of this adsorption system of MPc molecules onto the substrate. MPc molecules can potentially be employed for electrostatic doping of non-reactive substrates (for example 2D semiconductor materials), will lead to various applications such as sensors and electronics, and hence MPc become a model system for surface chemistry and nanotechnology. Tytanyl pthalocyanine (TiOPc) is another interesting molecule of pthalocyanine family having anisotropic intermolecular interactions. In this study, TiOPc electrostatic interactions with two nonreactive 2D semiconductor substrates, graphene and MoS2, were studied. We have carried out first principle density functional theory (DFT) calculations and theoretical analysis to explore the structural and electronic properties of mono- and bi-layer of TiOPc molecule on both graphene and MoS2. The adsorption of mono- and bi-layer films of TiOPc on graphene shows that there is a net 0.047 electrons and 0.016 electrons per TiOPc molecule charge transfer takes place from the graphene surface, respectively. Conversely, a net amount of 0.058 electrons and 0.029 electrons per TiOPc molecule charge transfer take place to the MoS2 surface in case of mono- and bi-layer of TiOPc, respectively. Moreover, we find that the bandgaps of graphene/TiOPc(mono-and bi-layer) and MoS2/TiOPc(mono-and bi-layer) heterostructures decrease with increasing number of TiOPc layers. Our results suggest that the band gap of 2D semiconductors, MoS2/TiOPc and graphene/TiOPc heterostuctures, could be engineered with atomic layer precision by controlling the number of TiOPc layer deposited on the 2D substrate, which could serve as a potential candidate for both sensor and advanced electronics applications.