Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV23)
DOI: https://doi.org/10.29363/nanoge.hopv.2023.009
Publication date: 30th March 2023
In this work I will present two new concepts related to hybrid perovskite synthesis and devices.
Chiral molecules were implemented into hybrid perovskite forming 2D hybrid perovskite with chirality properties. We used the two enantiomers R)-(+)-α-Methylbenzylamine (R-MBA) and, (S)-(-)-α-Methylbenzylamine (S-MBA). The chirality is manifested at low n values and pure 2D structure measured by circular dichroism (CD). The anisotropy factor (gabs) decreased by an order of magnitude when decreasing the n value achieving 0.0062 for pure 2D. Ab initio many-body perturbation theory successfully describes the band gaps, absorbance and CD measurements. For the first time these quasi 2D chiral perovskites were integrated into the solar cell. Using circular polarization (CP) and cut off filter we were able to distinguish the chirality effect from the solar cells photovoltaic response.
In the second part we developed unique fully printable mesoporous indium tin oxide (ITO) perovskite solar cell. In this structure, the perovskite is not forming a separate layer but fills the pores of the triple-oxide structure. One of the advantageous of this solar cell structure is the transparent contact (mesoporous ITO) which permit the use of this cell structure in bifacial configuration without the need for additional layers or thinner counter electrode. We performed full characterizations on both sides (i.e. ITO-side and glass-side) and elucidate the solar cell mechanism, where the glass side show 15.3% efficiency compare to 3.8% of the ITO-side. Further study of the mechanism shows that the dominant mechanism when illuminating from the glass-side is Shockley-Read-Hall recombination in the bulk, while illuminating from the ITO-side show recombination in multiple traps and inter gap defect distribution which explain the poor PV performance of the ITO-side. Electrochemical impedance spectroscopy shed more light on the resistance and capacitance. Finally, we demonstrate 18.3% efficiency in bifacial configuration. This work shows a fully printable solar cell structure which can function in bifacial configuration.