Luminescence-Based Implied Voltage Imaging of Tandem Solar Cells Using Bandpass Filters

Area of Science:

• Materials Science
• Renewable Energy
• Optoelectronics

Background:

• Tandem solar cells offer higher efficiencies but require precise characterization of individual sub-cells.
• Understanding voltage variations across the device is crucial for performance optimization.
• Existing imaging techniques may be confounded by optical properties, limiting accuracy.

Purpose of the Study:

• To develop a luminescence-based imaging technique for selective measurement of implied voltages in tandem solar cells.
• To validate the technique's accuracy and applicability across various device configurations.
• To demonstrate its utility for local performance analysis and defect identification.

Main Methods:

• Utilizing a narrow bandpass filter to capture luminescence emission, making the signal independent of device optical properties.
• Applying the technique to two-terminal perovskite/silicon tandem solar cells with diverse structures and compositions.
• Validating results through both numerical simulations and experimental measurements.

Main Results:

• The luminescence imaging technique accurately reveals implied voltage variations within tandem solar cells.
• Implied voltage images for each sub-cell were obtained with a maximum relative error of 1%.
• The method demonstrated the capability to generate local current-voltage curves.

Conclusions:

• The developed luminescence-based technique provides a robust and accurate method for imaging implied voltages in tandem solar cells.
• This technique is a valuable tool for optimizing tandem solar cell performance, enabling defect analysis, and predicting device longevity.
• It facilitates the scale-up and development of advanced perovskite/silicon tandem solar cell technologies.