Enhanced mobility CsPbI₃ quantum dot arrays for record-efficiency, high-voltage photovoltaic cells

Area of Science:

• Materials Science
• Nanotechnology
• Photovoltaics

Background:

• Perovskite quantum dots (QDs) offer advantages in colloidal synthesis and processing for solar cells.
• Cesium lead iodide (CsPbI3) QDs are suitable for top cells in multijunction solar devices due to their tunable bandgap and small open-circuit voltage (VOC) deficit.
• Charge carrier mobility in QD films is influenced by the chemical environment at quantum dot junctions.

Purpose of the Study:

• To develop lead halide perovskite QD films with improved surface chemistry via A-site cation halide salt (AX) treatments.
• To investigate the impact of AX treatments on charge carrier mobility and film properties.
• To enhance the efficiency of QD solar cells through optimized film fabrication.

Main Methods:

• Development of lead halide perovskite QD films using tailored surface chemistry.
• Application of A-site cation halide salt (AX) treatments to tune QD-QD coupling.
• Characterization of film properties, including charge carrier mobility and photocurrent.

Main Results:

• AX treatments successfully tuned the surface chemistry of perovskite QD films.
• The treatments doubled charge carrier mobility within the QD films.
• A record certified QD solar cell efficiency of 13.43% was achieved.

Conclusions:

• AX treatments are an effective method for improving charge transport in perovskite QD films.
• Optimized QD film fabrication via surface chemistry modification leads to enhanced solar cell performance.
• These findings pave the way for higher efficiency all-perovskite multijunction solar cells.