Mesoporous indium tin oxide perovskite solar cells in bifacial configuration

In this work, we present a fully printable mesoporous (mp) indium tin oxide (ITO) perovskite solar cell. The solar cell structure consists of triple-oxide screen-printed mp layers. In this structure, the perovskite does not form a separate layer but fills the pores of the triple-oxide structure. The perovskite is utilized as both a light harvester and a hole transporting material. One of the advantages of this solar cell structure is the transparent contact (mp ITO), which permits the use of this cell structure in a bifacial configuration without the need for additional layers or thinner counter electrodes. We performed photovoltaic (PV) measurements on both sides (i.e. ITO side and glass side), where the glass side shows 15.3% efficiency compared to 4.4% 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 shows recombination in multiple traps and inter-gap defect distribution, which explains the poor PV performance of the ITO side. Electrochemical impedance spectroscopy sheds more light on the resistance and capacitance. Finally, we demonstrate 18.3% efficiency in the bifacial configuration. This work presents a fully printable, large-scale suitable solar cell structure that can function in a bifacial configuration.