伊藤 省吾

Abstract Carbon‐based multiporous‐layered‐electrode perovskite solar cells (MPLE‐PSCs) offer excellent stability and low‐cost, fully printable fabrication, but device performance is often limited by electrical leakage between electrodes. Here, we demonstrate that the electrical insulation of MPLE structures, measured as resistance (Ω) before perovskite infiltration, strongly predicts final device performance. Statistical analysis of over 300 devices shows that high‐insulation cells (10 ⁵ –10 ⁷  Ω) consistently achieve high J _SC , V _OC , fill factor, and power conversion efficiency, whereas low‐insulation cells suffer from severe leakage. We identify the mesoporous ZrO ₂ spacer layer as the dominant source of insulation and show that its thickness and thermal treatment are critical. Drying the ZrO ₂ layer at 200 °C preserves the porous structure and enables uniform carbon printing, while pre‐sintering at 500 °C causes mechanical damage and degrades insulation. This simple pre‐infiltration insulation screening provides a practical route to improve yield and scalability of carbon‐based perovskite solar cells.

Hydrogen polymer electrolyte fuel cells (PEFCs) are key technologies for achieving a low-carbon society, but conventional oxygen reduction reaction (ORR) catalysts sucg as Pt/C suffer from degradadation of carbon supports during operation. To overcome this limitation, we developed a nanostructured catalyst support by coating tin oxide (SnO2) nanoparticles with cobalt-manganese oxide (CMO), enabling nanoscale interface engineering. The CMO layer was formed via electroless deposition of cobalt-manganese oxyhydroxide (CMOH) followed by thermal conversion at 300 °C. Platinum (Pt) and carbon black (Ketjenblack®, KB) were then incorporated to obtain Pt-CMO-SnO2/KB. The resulting catalyst exhibited a 1.97-fold higher mass activity (119.9 A gPt-1 at 0.9 V) than conventional Pt/C and showed significantly enhanced durability, retaining 33% more mass activity after voltage cycliying. Scanning transmission electron microscopy (STEM) combined with energy-dispersive X-ray spectroscopy (EDX) revealed selective Pt deposition on the CMO surface rather than on carbon. X-ray photoelectron spectroscopy (XPS) further confirmed strong metal-support interactions that suppressed Pt agglomeration and detachment. This nanointerface-guided design provides as effective and scalable strategy for improving ORR activity and durability in next-generation PEFC catalysts.