Use of Peruvian dye, Ayrampo (Opuntia Soehrensii) as a sensitizer in Grätzel cells of TiO2, using graphite as a counter-electrode

Abstract

In the search for new dyes that make large-scale manufacturing of dye sensitized solar cells, cheaper materials are sought rather than conventional ones that are produced only in laboratories. As is known, an application of nanotechnology is the conversion of solar energy into electrical energy through photovoltaic technology, since nanomaterials and/or films with nanometric thicknesses are used for the manufacture of sensitized solar cells with dye; on the other hand, the use of natural dyes as a sensitizer within the Grätzel cell of TiO2 is proposed. These cells are made up of overlapping layers, each one has a determining and specific function, the dye being in charge of absorbing the photons and turning them into electrons, having great importance in the open circuit voltage and in the efficiency of the cell. The TiO2 electrodes prepared by the Doctor Blade method were later sintered and then sensitized with the Ayrampo. These pigmented films were characterized by FTIR, to find the types of bonds present. The cells were characterized by their current versus voltage curve to determine: FF, ISC, VOC, VPMM, IPMM, and the efficiency of the solar cell. The impedance characterization of the cell was also performed to observe its internal behavior. The principle of operation of the cell is given by the photovoltaic effect, when solar radiation falls on the cell, the photon collides with the dye molecule, this gives enough energy to excite it and make the electron escape from the molecule of the molecule of the dye and move to the semiconductor TiO2, when this occurs, a flow of electrons is created (e-). Then the liquid electrolyte (I-/I-3) regenerates the dye with one of its electrons, electrons travel and create an electrical circuit. The I-V curve shows that the solar cell has a maximum efficiency of 0.75%.