Selective Deposition of Insulating Metal Oxide in Perovskite Solar Cells with Enhanced Device Performance

Preparations of MgO Nanoparticles by a Poly(acrylic acid)s Template-Assisted Method and Photovoltaic Performances of Dye-Sensitized Solar Cells based on MgO lnterlayer

Magnesium oxide (MgO) nanoparticles are commonly used to enhance the reactivity and performance of devices and systems in various applications, primarily due to the heat-resistance, binding, and alkaline properties of MgO. However, most of the methods used to synthesize MgO nanoparticles suffer from nonuniform particle size distributions that make it difficult to manufacture stable particles. In this study, uniform magnesium oxide (MgO) nanoparticles were developed for TiO2 photoelectrodes of dye-sensitized solar cells (DSSCs) to enhance their interfacial resistances. The uniform MgO nanoparticles were synthesized from MgO 93% using a poly(acrylic acid) template-assisted method. The particle size and crystalline structure of MgO nanoparticles were characterized by NANOPHOX particle size analysis, transmission electron microscopy, and X-ray diffraction. Multilayered TiO2 photoelectrodes containing interlayers of MgO nanoparticles were fabricated as photoelectrodes for DSSC devices, and their photovoltaic performances were investigated. When the MgO interlayer was introduced into the multilayered TiO2 photoelectrode, it not only increased the photocurrent value of the DSSC device but also improved its power conversion efficiency. The DSSC device containing the MgO interlayer and the scattering layer exhibited an open-circuit voltage of 0.74 V, a short-circuit current density of 14.60 mA/cm2, and a fill factor of 0.64 under a photointensity of 100 mW/cm2 at AM 1.5, resulting in an overall solar energy conversion efficiency of 6.94%. The application of an MgO interlayer in a DSSC device exhibited improved conductivity, charge transfer ability, and excellent device performance.

Efficient perovskite solar cells by combination use of Au nanoparticles and insulating metal oxide

Achieving high open-circuit voltage and high short-circuit current density simultaneously is a big challenge in the development of highly efficient perovskite solar cells, due to the complex excitonic nature of hybrid organic-inorganic semiconductors. Herein, we developed a facile and effective method to fabricate efficient plasmonic PSC devices. The solar cells were prepared by incorporating Au nanoparticles (NPs) into mesoporous TiO₂ films and depositing a MgO passivation film on the Au NP-modified mesoporous titania via wet spinning and pyrolysis of magnesium salt. The PSCs obtained by combining Au NPs and MgO demonstrated a high power conversion efficiency of 16.1%, with both a high open-circuit voltage of 1.09 V and a high short-circuit current density of 21.76 mA cm^-2. The device achieved a 34.2% improvement in the power conversion efficiency compared with a device based on pure TiO₂. Moreover, a significant improvement of the UV stability in the perovskite solar cell was achieved due to the combined use of Au NPs and insulating MgO. The fundamental optics and physics behind the regulation of energy flow in the perovskite solar cell and the concept of using Au NPs and MgO to improve the device performance were explored. The results indicate that the combined use of Au NPs and a MgO passivation film is an effective way to design high performance and high stability organic-inorganic perovskite photovoltaic materials.

Enhanced Stability of Perovskite Solar Cells through Corrosion-Free Pyridine Derivatives in Hole-Transporting Materials

The molecular structure of pyridine derivatives is critical to perovskite solar cell performance, especially stability. Most of the pyridine additives easily form complexes with perovskite. A new pyridine additive with a long alkyl chain substituted at its o-position does not corrode perovskite. The stability of devices containing this additive is the highest among the investigated cells.

Hierarchical nanostructures of metal oxides for enhancing charge separation and transport in photoelectrochemical solar energy conversion systems

Photoelectrochemical solar energy conversion systems, including photoelectrochemical water splitting and photoelectrochemical solar cells (dye-sensitized solar cells, DSSCs), are under intensive development aiming at efficiently harvesting and utilizing solar energy. Metal oxides carved into hierarchical nanostructures are thought to be promising for improving photoelectrochemical performance by enhancing charge separation and transport. Herein, we review the recent progress in the research on the design and applications of metal oxide hierarchical nanostructures in water splitting and DSSC systems with a view to understanding how they improve the device performance in terms of enhanced charge separation and transport properties. This review will end with a conclusion on metal oxide hierarchical nanostructures together with potential future research directions thereof.