Insulation Ability and Morphological Effect of ZrO2 Spacer Layer in Carbon-Based Multiporous Layered Electrode Perovskite Solar Cells

Fully printable carbon-based multiporous layered electrode perovskite solar cells (MPLE−PSCs) are close to being commercialized due to their excellent stability, their ability to easily be scaled up, and their amenability to mass production via non-vacuum fabrication processes. To improve their efficiency, it is important that detailed studies of the morphologies of mesoporous electrodes be carried out. In this study, we prepared five types of ZrO2 spacer layers for MPLE−PSCs, and the morphology of ZrO2 and device performance were evaluated using a scanning electron microscope, nitrogen adsorption/desorption measurements, electrode resistance measurements, UV-visible light reflectance measurements, and current density–voltage measurements. The results reveal that the adequate specific surface area and pore size distribution of mesoporous ZrO2 provided high insulation ability when used as spacers between electrodes and light absorbance, resulting in a 10.92% photoelectric conversion efficiency with a 23.22 mA cm−2 short-circuit current density. This information can serve as a guideline for designing morphologies useful for producing high-efficiency devices.