The Project aim. In this project we propose to investigate the electro-optical and magneto-optical properties of garnet films with nanostructured metallic surface profiles and mixed halide perovskite CH3NH3PbI3-xClx thin films which were recently emerged as promising candidates in solar cell applications.
These two types of materials expected to have large Faraday rotation of polarization vector. First we plan to synthesize these films and then measure their reflection and transmission coefficients in the optical region. Using these measurements we hope to reveal the refraction and extinction coefficients, their dependencies on wavelength and substitution concentration x. Using the capacity measurements we want to obtain static dielectric constant that plays important role in all excitonic considerations of these films. In the second stage of the project we plan to investigate the magneto-optical properties of these films. Particularly, we propose to measure Faraday rotation angle under external magnetic and pumped laser fields. We plan to develop a theory for dielectric permittivity tensor of these systems. The application of tight-binding models to photon and plasmon transport in two-dimensional periodical structures will be studied.
Current status. We have already treat compliance technology for the fabrication of CH3NH3PbI3-xClx films by combining of a thermal vacuum deposition of PbI2 following by chemical gas transport reaction in vapors of CH3NH3Cl and synthesized few samples of different thickness and concentration of x. We have prepared setups for reflection, transmission and Faraday angle measurements. We theoretically investigated the transport of excitons in the random field of impurities.
The project’ influence on progress in this area. Detailed knowledge of different parameters of these new materials will help to improve their photovoltaic performance. Observation of large Faraday rotation will open possibilities for different spintronic applications especially ultrafast spin switches, imaging and etc.
The participants’ expertise. The scientists taking part in the project have considerable experience in these field proved by their publications and participation in the international conferences. Project team members have many publications in leading journals on the topic of Project.
Expected results and their application.
§ Preparation of garnet films with different metallic surface profiles of Ag and Au
§ Synthesis of CH3NH3PbI3-xClx films of different thickness and concentration x by combining of a laser-assisted, thermal vacuum deposition and chemical gas transport reaction technologies
§ Transmission and Reflection coefficients and their spectral dependencies
§ Non-diagonal dielectric permittivity tensor of halide perovskite semiconductors
§ Tight-binding models for electrons with spin and photons
§ Faraday rotation angle and its dependence on concentration x
§ Polarization rotation angle for backscattered wave (Kerr effect)
§ Magneto-optical images obtained using magneto-plasmonic thin films. Technical approach and methodology. We will prepare different technological approaches including laser deposition, vacuum evaporation, gas transport reactions and spin-coating for the fabrication of CH3NH3PbI3-xClx and Ag+garnet thin films. Polarization modulation technique for the measurement of magneto-optical characteristics of thin films will be used. At processing modern packages will be used. For theoretical calculations we will use modern methods of theoretical physics.
