Energy and Materials Research

Biography

Biography: Alexander Kobryn

Abstract

Both descriptive and predictive modeling of structural properties of blends of PCBM or organic-inorganic hybrid perovskites of the type CH₃NH₃PbX₃ (X=Cl, Br, I) with P3HT, P3BT or some squaraine SQ dye sensitizer, including adsorption on TiO₂ clusters having rutile (110) surface, is presented with the use of a methodology that allows computing the microscopic structure of blends on the nanometer scale and getting insight on miscibility of its components at various thermodynamic conditions. The methodology is based on the integral equation theory of molecular liquids in the reference interaction site representation/model (RISM) and uses the universal force field. Input parameters for RISM, such as optimized molecular geometries and charge distribution of interaction sites, are derived with the use of the density functional theory methods. To compare the diff usivity of the PCBM in binary blends with P3HT and P3BT, respectively, the study is complemented with MD simulation. A remarkably good agreement with available experimental data and results of alternative modeling/simulation is observed for PCBM in P3HT system. We interpret this as a step-in validation of the use of our approach for organic photovoltaic and support of its results for new systems that do not have reference data for comparison or calibration. For the less studied P3BT, our results show that expectations about its performance in binary blends with PCBM may be overestimated, as it does not demonstrate the required level of miscibility and short-range structural organization. The performance of P3BT with perovskites, however, seems as expected. The calculated nanoscale morphologies of blends of P3HT, P3BT or SQ with perovskites, including adsorption on TiO₂, are all new and serve as an instrument in rational design of organic/hybrid photovoltaics. They are used in collaboration with experts who make prototypes or devices for practical applications.