Large-Scale Synthesis of Semiconducting Cu(In,Ga)Se₂ Nanoparticles for Screen Printing Application

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Copper indium gallium selenide (Cu(In,Ga)Se2) thin films are promising photoabsorbers for photovoltaics due to their excellent properties.
• Solution-processed thin-film deposition offers a cost-effective and high-throughput alternative for solar cell manufacturing.
• Current synthesis methods primarily yield tetragonal Cu(In,Ga)Se2 nanoparticles, limiting structural diversity.

Purpose of the Study:

• To develop a large-scale synthesis for Cu(In,Ga)Se2 nanoparticles with a non-tetragonal structure.
• To create an ink formulation using these nanoparticles for printing applications.
• To enable environmentally friendly, roll-to-roll production of photovoltaic systems.

Main Methods:

• Large-scale synthesis of Cu(In,Ga)Se2 nanoparticles with controlled size (10-70 nm) and specific metal ratios ([Cu]/[In + Ga] ≈ 0.8, [Ga]/[Ga + In] ≈ 0.3).
• Characterization of nanoparticle structure, confirming the wurtzite hexagonal phase.
• Dispersion of nanoparticles into a water-based ink formulation.
• Screen printing deposition of the ink to form thin films (≈4.5 µm thickness).

Main Results:

• Successfully synthesized high-quality Cu(In,Ga)Se2 nanoparticles with a wurtzite hexagonal structure.
• The nanoparticles exhibit broad absorption across visible and near-infrared spectra.
• The resulting screen-printed thin films show homogenous thickness, suitable for photovoltaic applications.

Conclusions:

• The developed synthesis method provides access to hexagonal Cu(In,Ga)Se2 nanoparticles, overcoming limitations of previous approaches.
• The nanoparticle ink formulation is compatible with screen printing, facilitating scalable fabrication.
• This work paves the way for sustainable, roll-to-roll manufacturing of efficient photovoltaic devices.