Ultrathin Hole Extraction Layer for Efficient Inverted Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Inverted perovskite solar cells (PSCs) commonly use poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT) as a hole transport layer (HTL).
• Traditional PEDOT HTLs in PSCs often lead to suboptimal device performance, characterized by reduced photocurrent and low open-circuit voltage (V_OC) around 0.95 V.

Purpose of the Study:

• To investigate the use of an ultrathin PEDOT layer as an HTL for efficient inverted PSCs.
• To analyze the impact of PEDOT layer thickness on transparency, conductivity, and film morphology.
• To demonstrate a facile method for improving PSC performance and reducing fabrication costs.

Main Methods:

• Fabrication of inverted PSCs utilizing ultrathin PEDOT layers as the HTL.
• Characterization of PEDOT film properties, including transparency, conductivity, and morphology.
• Comparison of device performance with PSCs using traditional thicker PEDOT layers.

Main Results:

• The ultrathin PEDOT layer significantly improved key performance metrics of the inverted PSCs.
• Notable enhancements were observed in short-circuit current density (J_SC), open-circuit voltage (V_OC), and overall power conversion efficiency.
• Ultrathin PEDOT films were readily achieved through simple dilution methods.

Conclusions:

• Employing an ultrathin PEDOT layer is an effective strategy to enhance the performance of inverted PSCs.
• This approach offers a straightforward and cost-effective route for PSC fabrication.
• The findings suggest a promising direction for the development of more efficient and economical perovskite solar cell technologies.