Studium segregace materiálu směsných halogenidových perovskitů pro solární články

Abstract

Perovskite solar cell is an advanced and potential technology. It is a candidate for a top cell for potential tandem solar cell and with bottom cell as conventional crystalline silicon. The evidence of high efficiency of these devices has made researchers and scientist curious to study the technology more in detail. The literature survey of this thesis sheds some light on the basics of solar cell technology. The thesis also gives briefs about few general terms used in photovoltaics. Moving further, the thesis goes into details about different types of solar cells. Since this study is focused on perovskite technology, the research done, focuses on perovskite technology in more detail. This thesis includes the preparation and study of Cs0.17FA0.83Pb(I0.6Br0.4)3 perovskite solar cell. The study of phase segregation in mixed halide perovskite layers and solar cells has been completed using the optical and electrical measurements for observing the structural and electrical parameter changes. Finished cells and layers on glass were either prepared or supplied by partner laboratory. Defects occurring in the perovskites are also a part of this research. In this study, the phase segregation which accounts for one of the defects in the perovskite structure has been studied. To realize the segregation of the cell, time sequence of light soaking and relaxation in the dark and comprehensive analysis of the measured data was performed. From the obtained graphs it can be said that the reason for degradation might be due to ion migration when the cell is exposed to light soaking. It was also observed that during relaxation cycle, the perovskite cell structure returned to its initial state. Additionally, this thesis includes the discussion of possible reasons for the degradation of sample due to illumination which comply with the theory from various papers. This thesis also includes the study of stability and susceptibility to segregation for 5 different perovskite compositions. The Br-I ratios of the samples were different, which resulted in FA0.83Cs0.17Pb(I0.68Br0.32)3 being more stable than other samples.

Perovskite solar cell is an advanced and potential technology. It is a candidate for a top cell for potential tandem solar cell and with bottom cell as conventional crystalline silicon. The evidence of high efficiency of these devices has made researchers and scientist curious to study the technology more in detail. The literature survey of this thesis sheds some light on the basics of solar cell technology. The thesis also gives briefs about few general terms used in photovoltaics. Moving further, the thesis goes into details about different types of solar cells. Since this study is focused on perovskite technology, the research done, focuses on perovskite technology in more detail. This thesis includes the preparation and study of Cs0.17FA0.83Pb(I0.6Br0.4)3 perovskite solar cell. The study of phase segregation in mixed halide perovskite layers and solar cells has been completed using the optical and electrical measurements for observing the structural and electrical parameter changes. Finished cells and layers on glass were either prepared or supplied by partner laboratory. Defects occurring in the perovskites are also a part of this research. In this study, the phase segregation which accounts for one of the defects in the perovskite structure has been studied. To realize the segregation of the cell, time sequence of light soaking and relaxation in the dark and comprehensive analysis of the measured data was performed. From the obtained graphs it can be said that the reason for degradation might be due to ion migration when the cell is exposed to light soaking. It was also observed that during relaxation cycle, the perovskite cell structure returned to its initial state. Additionally, this thesis includes the discussion of possible reasons for the degradation of sample due to illumination which comply with the theory from various papers. This thesis also includes the study of stability and susceptibility to segregation for 5 different perovskite compositions. The Br-I ratios of the samples were different, which resulted in FA0.83Cs0.17Pb(I0.68Br0.32)3 being more stable than other samples.