Inkjet Printing NiO-Based p-Type Dye-Sensitized Solar Cells

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Transparent p-type semiconductors are crucial for scalable electronic devices, particularly in photovoltaic and photocatalytic applications.
• Low-cost fabrication methods are needed to enable widespread use of these materials.

Purpose of the Study:

• To investigate the inkjet printing of mesoporous nickel oxide (NiO) films for the first time.
• To explore the effect of different thermal treatments on NiO film morphology and properties.
• To evaluate the performance of these NiO films in a p-type dye-sensitized solar cell (p-DSSC) configuration.

Main Methods:

• Sol-gel ink formulation using nickel chloride and Pluronic F-127 in a water/ethanol mixture.
• Inkjet printing of multilayer NiO films using a Dimatix printer.
• Controlled interlayer thermal treatments at 30 °C and 450 °C.
• X-ray photoelectron spectroscopy (XPS) to investigate the NiO formation mechanism.
• Performance evaluation in a p-DSSC with a novel push-pull dye (RBG-174) and iodine electrolyte.

Main Results:

• Mesoporous NiO films with dual-pore (nanoparticulate-nanofiber) structure obtained at 30 °C.
• Denser NiO films without dual structure obtained at 450 °C.
• Nickel hydroxide (Ni(OH)2) identified as an intermediate in NiO formation.
• Optimized NiO photocathodes (860 nm) with an additional NiOx layer achieved a short-circuit current density of 3.42 mA cm⁻².

Conclusions:

• Inkjet printing is a viable method for fabricating mesoporous NiO films.
• Thermal treatment significantly influences NiO morphology and performance in p-DSSC devices.
• An intermediate NiOx layer enhances the performance of NiO-based photocathodes.