Ceramic Nano-particle/Substrate Interface Bonding Formation Derived from Dynamic Mechanical Force at Room Temperature: HRTEM Examination

The bonding of TiO₂ nano-particle/substrate is a critical factor influencing the performance of dye-sensitized solar cells. In order to reveal the bonding properties at TiO₂ nano-particle/substrate interface, high-resolution transmission electron microscopy (HRTEM) analysis was adopted to TiO₂ coatings prepared by three different approaches. In the HRTEM analysis, the effective bonding mode is allowed to distinguish from the false image overlapping. Results show that large areas of effective bonding between nano-TiO₂ particles and the substrate surface formed in the room temperature cold sprayed coating and mechanically pressed coating, while only limited interface areas with the effective bonding were observed in the coating deposited by non-pressed method. These results confirm that both high impact pressure during the room temperature cold spraying and mechanical pressure contribute to the bonding formation at the particle/substrate interface.