Simultaneously Enhancing the Efficiency and Stability of Perovskite Solar Cells by Using P3HT/PEDOT:PSS as a Double...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) face stability challenges.
• Poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is a common hole transport layer (HTL) but can corrode ITO and is hydrophilic, reducing device stability.
• Improving PSC efficiency and operational lifetime is crucial for commercial viability.

Purpose of the Study:

• To enhance the efficiency and stability of inverted perovskite solar cells (PSCs).
• To address the limitations of PEDOT:PSS as an HTL in PSCs, specifically its hydrophilicity and potential for ITO corrosion.
• To investigate the effect of incorporating Poly (3-hexylthiophene-2,5-diyl) (P3HT) onto the PEDOT:PSS layer.

Main Methods:

• Modification of the PEDOT:PSS surface with P3HT to create a hydrophobic bilayer HTL.
• Fabrication of inverted PSCs using the modified HTL.
• Characterization of device performance, including power conversion efficiency (PCE) and stability under prolonged operation.
• Analysis of perovskite film morphology and properties.

Main Results:

• Incorporation of P3HT significantly enhanced the hydrophobicity of the PEDOT:PSS layer.
• The PEDOT:PSS/P3HT bilayer promoted the formation of large-grain perovskite films.
• PSCs with the P3HT-modified HTL achieved a PCE of 19.78%, a 16% increase compared to reference cells (17.04%).
• Devices maintained over 90% of their initial PCE after 1000 hours, while reference devices dropped below 70%.

Conclusions:

• P3HT effectively mitigates the hydrophilic nature of PEDOT:PSS, improving PSC stability.
• The P3HT modification concurrently enhances both the efficiency and long-term operational stability of PSCs.
• Bilayer HTLs combining PEDOT:PSS and P3HT offer a promising strategy for developing high-performance and durable perovskite solar cells.