Investigation of 1.7–Diphenyl-Substituted BODIPY Nanosized Films for Photoconverters
Students Name: Ivanochko Liubomyr Ivanovych
Qualification Level: magister
Speciality: Electronic Equipment and Devices
Institute: Institute of Telecommunications, Radioelectronics and Electronic Engineering
Mode of Study: full
Academic Year: 2020-2021 н.р.
Language of Defence: ukrainian
Abstract: Ivanochko L.I., Stakhira P.Y. (head). Investigation of 1.7 of diphenyl-substituted BODIPY nanosized films for photoconverters. Master’s thesis. - Lviv Polytechnic National University, Lviv, 2020. Extended annotation. Dye-sensitized solar cells provide a technically and economically sound alternative concept to modern p-n junction photovoltaic devices. Unlike conventional systems, where the semiconductor takes on the task of absorbing light and transporting the charge carrier, the two functions are separated here. Light is absorbed by a sensitizer, which is fixed on the surface of the semiconductor. Charge separation occurs at the interface by photoinduced introduction of an electron from the dye into the conduction band of a solid. The carriers are transported in the conduction band of the semiconductor to the charge collector. The use of sensitizers with a wide absorption band in combination with oxide films of nanocrystalline morphology allows to collect a large proportion of solar radiation. The conversion of an incident photon into an electric current is achieved in a large spectral range extending from the UV to the near-IR region. The total efficiency of solar energy conversion currently exceeds 10%. There are good prospects to produce these cells at a lower cost than conventional devices. Here we present the current state of the field, discuss new concepts of sensitized nanocrystalline solar cell, including heterojunction options, and analyze the prospects for future technology development. There are good prospects to produce these cells at a lower cost than conventional devices. Object of research - processes in the made nanofilm organic photoconverters. They are formed by thermovacuum spraying and casting. For light-transforming heterostructures based on chalcogenides and CuInS2, the conversion efficiency was obtained at the level of 17-19.2%. However, the presence of toxic cadmium in these heterostructures stimulates the search for replacement of CdS and CdTe layers. Promising substances for this are the photosensitive organic semiconductor BODIPY, as well as CuI. This is due to the fact that in the surface of organic semiconductors there are no broken covalent bonds and they should not create additional centers of capture and recombination at the interface with CuInS2. Subject of research - Increasing the level of characteristics and durability of nanoscale films for photoconverters. The purpose of the study is to study the properties of the n-type CIS surface, their change during the application of thin organic layers and the search for organic semiconductors that are promising for creating a barrier with CIS films. The investigated CISCul layers have a significant photosensitivity in the range of 1.5-3.0 eV. Approximation of the long-wavelength edge of the dependence V2s = f (h?) gives the value of the band gap width Eg = 1.46 ± 0.02 eV. The weak influence of the external electric field on the surface photovoltaic Vs, when the sample is illuminated by strong absorbing light, and the decrease in photoelectricity with increasing h? in the region 1.55-3.0 eV indicate the formation on the surface of the CISCul layer of high concentrations of surface charge centers. Key words - heterojunction, exciton, BODIPY, organic film. Referens. Баришніков Г.В. Органічна електроніка: підручник / Д. Ю. Волинюк, І. І. Гельжинський, З. Ю. Готра, Б.П. Мінаєв, П. Й. Стахіра, В. В. Черпак; за ред. З. Ю. Готри. – 2- вид., зі змін. допов. – Львів: Видавництво Львівської політехніки, 2019. –324 с. В. П. Мачулін. Сонячна енергетика: порядок денний для світу й України / Вісник Національної академії наук України. Загальнонауковий та громадсько-політичний журнал. — 2011, № 5. Herwig, L. O. Cherry Hill revisited: Background events and photovoltaic technology status.Chem. Phys,—2005. 785 p. L. Waw Li. Processing Additives for Improved Efficiency from Bulk Heterojunction Solar Cells./ Christoph J. , Ji Sun , Alan J., Guillermo C .Journal of the American Chemical Society. –2008, № 45. Rogers M. Time-Resolved Structural Evolution of Additive-Processed Bulk Heterojunction Solar Cells / James T., Guillermo C. Journal of the American Chemical Society. –2008, № 63.