Solution-processed MoO₃ thin films as a hole-injection layer for organic solar cells

Area of Science:

• Materials Science
• Organic Electronics
• Thin Film Deposition

Background:

• Organic solar cells require efficient hole-injection layers (HILs) for optimal performance.
• Current HILs include PEDOT:PSS and thermally evaporated MoO3 (eMoO3), with limitations in processing or stability.
• Developing cost-effective and high-performance HILs is crucial for advancing organic photovoltaics.

Purpose of the Study:

• To introduce a novel sol-gel-based technique for fabricating molybdenum trioxide (MoO3) thin films.
• To evaluate the performance and stability of solution-processed MoO3 (sMoO3) as a HIL in organic solar cells.
• To compare sMoO3 HILs with conventional PEDOT:PSS and eMoO3 HILs.

Main Methods:

• Sol-gel synthesis of MoO3 precursor solutions.
• Spin-coating or printing techniques for depositing sMoO3 films.
• Fabrication and characterization of organic solar cells utilizing sMoO3 HILs.
• Performance testing including efficiency, stability, and shelf lifetime analysis.

Main Results:

• Solution-processed MoO3 (sMoO3) films exhibit performance comparable to PEDOT:PSS and eMoO3 HILs.
• The optimal annealing temperature for sMoO3 aligns with thermodynamic predictions.
• Devices incorporating sMoO3 demonstrate a shelf lifetime similar to those with eMoO3.

Conclusions:

• Sol-gel fabrication offers a viable and effective method for producing MoO3 HILs for organic solar cells.
• sMoO3 presents a promising alternative to existing HILs, suitable for solution-processed and thermally evaporated organic solar cells.
• The developed technique contributes to the advancement of low-cost, high-performance organic photovoltaic devices.