Preparation and layer-by-layer solution deposition of Cu(In,Ga)O2 nanoparticles with conversion to Cu(In,Ga)S2 films

Area of Science:

• Materials Science
• Nanotechnology
• Thin Film Deposition

Background:

• Copper indium gallium sulfide (CIGS) is a key material for thin-film solar cells.
• Developing scalable and cost-effective CIGS thin-film formation methods is crucial for photovoltaic applications.

Purpose of the Study:

• To present a novel method for CIGS thin film formation using layer-by-layer (LbL) assembly of copper-indium-gallium oxide (CIGO) nanoparticles.
• To evaluate the suitability of different polyelectrolytes for fabricating robust CIGO/polymer multilayer films.

Main Methods:

• Novel flame-spray pyrolysis for CIGO nanoparticle synthesis.
• LbL assembly using CIGO nanoparticles and polyelectrolytes (polydopamine - PDA, or polystyrenesulfonate - PSS) on various substrates.
• Oxidation and high-temperature sulfurization in hydrogen sulfide (H2S) to convert CIGO to CIGS.

Main Results:

• PDA/CIGO-PAH films exhibited enhanced mechanical robustness and high-temperature tolerance compared to PSS/CIGO-PAH films.
• PSS/CIGO-PAH films showed poor adhesion and particle diffusion during sulfurization.
• Complete conversion of CIGO to CIGS was confirmed by X-ray diffraction.

Conclusions:

• LbL assembly of CIGO nanoparticles offers a promising route for CIGS thin film fabrication.
• PDA as a polyelectrolyte is superior for creating stable CIGS precursor films suitable for high-temperature processing and sulfurization.