Thin film solid oxide fuel cells (TF-SOFCs) are attracting attention due to their ability to operate at comparatively lower temperatures (400-650 °C) that are unattainable for conventional anode-supported SOFCs (650-800 °C). However, limited cathode performance and cell scalability remain persistent issues. Here, we report a new approach of fabricating yttria-stabilized zirconia (YSZ)-based TF-SOFCs via a scalable magnetron sputtering process. Notable is the development and deposition of a porous La0.6Sr0.4Co0.2Fe0.8O2.95(LSCF)-based cathode with a unique fibrous nanostructure. This all-sputtered cell shows an open-circuit voltage of ∼1.0 V and peak power densities of ∼1.7 and ∼2.5 W/cm2 at 600 and 650 °C, respectively, under hydrogen fuel and air along with showing stable performance in short-term testing. The power densities obtained in this work are the highest among YSZ-based SOFCs at these low temperatures, which demonstrate the feasibility of fabricating exceptionally high-performance TF-SOFC cells with distinctive dense or porous nanostructures for each layer, as desired, by a sputtering process. This work illustrates a new, potentially low-cost, and scalable platform for the fabrication of next-generation TF-SOFCs with excellent power output and stability.

An all-sputter process has been developed and optimized to fabricate high-performance thin-film solid oxide fuel cells (TF-SOFCs) using conventional materials. The process involves sequential sputtering of cell components onto a porous substrate. An example structure comprises of an anode such as nickel-yttria stabilized zirconia (Ni-YSZ), an electrolyte such as YSZ, an interlayer such as gadolinium doped ceria (GDC), and then a cathode such as lanthanum strontium cobalt perovskite (LSC)-GDC. These are sputtered onto a porous substrate such as anodized aluminum oxide (AAO). Process conditions and sputtering procedures have been tailored and engineered to produce components with desired structural characteristics, i.e., a fully dense electrolyte and interlayer and a porous anode and cathode. The porous electrodes show a columnar structure with branch-like nano-fibers. Sputtered TF-SOFCs exhibit superior performance at reduced temperatures; for example, the peak power density was about 3.0 W/cm2 at 650oC (with H2 for the cell Ni-YSZ/YSZ/GDC/LSC-GDC) and the peak power density was about 2.6 W/cm2 at 700oC (with CH4 for the cell Ni-YSZ/YSZ/GDC/LSC-GDC).

Metal halide perovskites have witnessed great success in green, red, and near-infrared light-emitting diodes (LEDs), yet blue LEDs still lag behind. Reducing undesired energetic disorders – broad n-phases and halide segregation – is considered as the most critical strategy to further improve the performances. Here, the study reports a newly designed and synthesized di-ammonium ligand with rigid π-conjugated rings and additional methyl groups to construct Dion–Jacobson (DJ) structure. Augmented coordination from the extra ammonium site and increased effective bulkiness from methyl groups lead to better distribution control over conventional mono-ammonium ligands. This enhances the radiative recombination of blue emissions in the film with homogeneous energy landscape and improved surface morphology, as evidenced by a series of imaging and mapping techniques. As a result, it demonstrates DJ perovskite LEDs (PeLEDs) with peak external quantum efficiencies of ≈4% at 484 nm and ≈11% at 494 nm, which are among the top reported for pure DJ phase-based PeLEDs in the corresponding wavelength regions. The results deepen the understanding of regulating energetic disorders in perovskite materials via molecular engineering.