Theoretical studies of the temperature distribution during laser heating of the TiO2 precursor film on the FTO/glass substrate have been carried out. The simulation was performed on the basis of a numerical solution of the heat equation in the Matlab program to determine the energy density of the laser radiation necessary for crystallization of TiO2. It was shown that on the surface of the TiO2 precursor the temperature reaches a maximum value at a time point of 133 ns with the Gaussian temporal form of the laser pulse. The optimum energy density for crystallization of the TiO2 precursor film with the nanosecond pulse duration is 1.3-1.6 J/cm2, when the film thickness temperature corresponds to 400-500 °C. The obtained results of the simulation are consistent with experimental studies.
Keywords: numerical simulation, laser heating, temperature distribution, TiO2 film, solar cell
Nanocrystalline TiO2 films are used as transparent layer n-type conductivity in the perovskite solar cells. The work presents the numerical diffusion-drift modeling of the transport processes and the accumulation of charge carriers in the heterostructure of TiO2 / perovskite / p-type semiconductor. The basis of the simulation put stationary physical and topological model based on drift-diffusion equations and semiconductor system allowing to model perovskite solar cells with a variety of electro-technological and constructive parameters. Obtained photovoltaic solar cell characteristics and plotted the efficiency of the TiO2 film thickness. The optimal thickness of the TiO2 film is 50-100 nm, thereby increasing the perovskite solar cell efficiency.
Keywords: Solar cell, thin film, titanium dioxide, p-i-n structure, numerical modeling
A numerical model of the laser annealing TiO2 film on the TCO / glass substrate with radiation of a wavelength of 1064nm (Nd: YAG laser) to the crystallization and its use in solar cells perovskite. The modeling used a numerical finite difference method for solving a system of one-dimensional unsteady heat conduction differential equations. As a result, laser annealing temperature distribution obtained in the process of modeling the structure of TiO2 / TCO / glass substrate by varying the laser power. It is shown that a high laser power (30-100 watts) is enough for an effective transition organometallic precursor of TiO2 in the crystalline phase of anatase TiO2 (transition temperature of 400-600 °C) for a short period of time (60 sec.) due to the direct absorption of photons laser radiation. It is found that for experimental studies should be used laser power of 30-70 watts, since a higher power (e.g., 100 W) raises the temperature of the substrate above its melting point (for example, for glass 650 ° C).
Keywords: Numerical modeling, laser annealing, TiO2 film, heat equation, solar cell