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

In this work, a novel real-time current-voltage (J-V) absorbance spectroscopy (RTJAS) setup is introduced for directly observing halide segregation in mixed halide perovskite solar cells under broadband light illumination, simulating solar exposure. The setup incorporates a broadband light source calibrated to one sun irradiation and a CMOS camera for simultaneous capture of all diffracted wavelengths. J-V measurements are performed concurrently with absorbance spectra collection, enabling in situ analysis of light-induced degradation due to halide segregation, including bandgap shifts and cell performance data. Comparison of photoluminescence measurements with RTJAS data reveals differing rates of bandgap decrease, underscoring the advantages of real-time measurement techniques. The work highlights the importance of accounting for experimental conditions, such as humidity and voltage injection, which can accelerate halide segregation, ultimately emphasizing the need for careful consideration of experimental conditions to accurately characterize perovskite solar cell behavior under realistic conditions. The study introduces real-time J-V absorbance spectroscopy for observing halide segregation in mixed halide perovskite solar cells under broadband light. This novel setup enables concurrent J-V measurements and absorbance spectra collection, offering in situ analysis of light-induced degradation. The research emphasizes the significance of experimental conditions like humidity and voltage injection, advocating for meticulous characterization of perovskite solar cells under realistic conditions.image