Organic Solar Cells Based on WO2.72 Nanowire Anode Buffer Layer with Enhanced Power Conversion Efficiency and Ambient...

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Conventional PEDOT:PSS is widely used in organic solar cells (OSCs) but faces limitations.
• Alternative anode buffer layers are needed for scalable OSC manufacturing.
• Tungsten oxide (WO3) has shown potential, but existing forms have processing challenges.

Purpose of the Study:

• To investigate the potential of a specific tungsten oxide, WO2.72 (W18O49) nanowires (nw-WO2.72), as an anode buffer layer in OSCs.
• To evaluate the performance and stability of OSCs using nw-WO2.72 compared to PEDOT:PSS.
• To understand the mechanisms behind performance enhancement.

Main Methods:

• Fabrication of nw-WO2.72 films for use as anode buffer layers in OSCs.
• Fabrication and characterization of OSC devices using different polymer and small molecule active layers (e.g., PTB7:PC71BM, p-DTS(FBTTh2)2:PC71BM).
• Performance testing including power conversion efficiency (PCE) and ambient stability assessments.

Main Results:

• The nw-WO2.72 film demonstrated high optical transparency.
• Significant improvements in PCE were observed for OSCs using nw-WO2.72 compared to PEDOT:PSS across multiple active layers.
• Enhanced short-circuit current density (Jsc) was attributed to oxygen vacancies and surface structures in nw-WO2.72, facilitating better charge extraction.
• OSCs with nw-WO2.72 exhibited improved ambient stability.

Conclusions:

• WO2.72 nanowires are a viable and effective alternative anode buffer layer for organic solar cells.
• The use of nw-WO2.72 enhances both the power conversion efficiency and operational stability of OSCs.
• nw-WO2.72 presents a promising material for future large-scale manufacturing of efficient and stable organic solar cells.