High-Performance and Stable Perovskite/Organic Tandem Solar Cells Enabled by Interconnecting Layer Engineering

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite/organic tandem solar cells (PO-TSCs) are gaining attention for high efficiency and stability.
• The interconnecting layer (ICL) is crucial for PO-TSC performance, requiring optimized charge transport and recombination.
• Effective ICL design enhances charge carrier extraction and recombination balance between subcells.

Purpose of the Study:

• To optimize the ICL in PO-TSCs for improved performance.
• To investigate the effect of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) modification on the hole transport layer (HTL) within the ICL.
• To establish a strategy for high-performance PO-TSC through ICL engineering.

Main Methods:

• Modification of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) as the HTL in the ICL using 2PACz.
• Tuning the concentration of 2PACz solution to control its coverage on PEDOT:PSS.
• Fabrication and characterization of PO-TSCs with the modified ICL.

Main Results:

• The coverage of 2PACz on PEDOT:PSS significantly impacts PO-TSC performance.
• The PEDOT:PSS/2PACz structure enhances charge carrier extraction to the charge recombination layer (CRL).
• Optimized PO-TSCs achieved a power conversion efficiency (PCE) of 25.26%, compared to 23.57% for the control device, with improved stability.

Conclusions:

• ICL engineering using 2PACz modification of PEDOT:PSS is an effective strategy for high-performance PO-TSCs.
• The optimized ICL facilitates balanced charge carrier recombination and reduces parasitic absorption.
• This approach offers a pathway to enhanced efficiency and stability in perovskite/organic tandem solar cells.