Real Time Observation of Halide Segregation in Mixed Halide Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Spectroscopy

Background:

• Mixed halide perovskite solar cells are promising for renewable energy applications.
• Halide segregation is a key degradation pathway affecting device performance and stability.
• Accurate characterization of degradation mechanisms under operational conditions is crucial.

Purpose of the Study:

• To introduce a novel real-time current-voltage (J-V) absorbance spectroscopy (RTJAS) setup.
• To enable direct observation of halide segregation in mixed halide perovskite solar cells.
• To analyze light-induced degradation and its impact on cell performance in situ.

Main Methods:

• Development of a RTJAS setup with a calibrated broadband light source and CMOS camera.
• Simultaneous J-V measurements and absorbance spectra collection under one-sun irradiation.
• Comparison with photoluminescence measurements to validate real-time analysis.

Main Results:

• RTJAS successfully observed halide segregation and associated bandgap shifts in real-time.
• Light-induced degradation was quantified through simultaneous J-V and spectral data.
• Discrepancies in bandgap decrease rates were observed compared to photoluminescence, highlighting RTJAS advantages.

Conclusions:

• The RTJAS technique provides valuable insights into perovskite solar cell degradation.
• Experimental conditions like humidity and voltage significantly influence halide segregation rates.
• Accurate characterization requires considering environmental and operational factors for realistic perovskite solar cell assessment.