Why Does the Forward Scan Show Lower Efficiency in Perovskite Solar Cells?

In summary, when working with perovskite solar cells, the J-V curve is an important measurement for determining device performance. The reverse scan is typically performed before the forward scan and any differences in the curves, known as hysteresis, can be attributed to defects and shortcomings in the perovskite material. However, even when directly performing the forward scan, there is still a decrease in efficiency compared to the reverse scan. This suggests that the material and chemistry are still unstable and further experimentation is needed to find the most efficient and stable testing sequence. The main factors that are generally blamed for this decrease in efficiency are ferroelectric polarization, ion migration, charge trapping, and capacitive effects. Further research can be found in the
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Mayan Fung
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TL;DR Summary
Why does the forward and reverse J-V scan of a perovskite solar cell is different?
Hi all, I am working on perovskite solar cell related studies. J-V curve (current density-voltage curve) is one of the important measurements to determine the performance of the device. In practice, we perform the reverse scan first then then followed by the forward scan. There is usually a difference in the curve (worse in the forward scan) which we called hysteresis due to some defects and shortcomings of perovskite.

However, even if I don't perform the reverse scan first (i.e. I directly perform the forward scan), the forward scan still shows a worse efficiency than the reverse one. What is the reason?
 
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The cells are being changed by the order of initial testing. That suggests the formation process has not been completed and the chemistry is still unstable. You need to experiment to find the testing sequence that produces the most efficient and stable cell.

We would need to know more about the fabrication process you use, what light exposure occurs and how you perform the scans, to identify what the changes in the material and performance might be.

https://en.wikipedia.org/wiki/Perovskite_solar_cell#Stability
 
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FAQ: Why Does the Forward Scan Show Lower Efficiency in Perovskite Solar Cells?

What is a Perovskite solar cell J-V scan?

A Perovskite solar cell J-V scan is a measurement technique used to analyze the performance of a perovskite solar cell. It involves sweeping a range of voltages across the solar cell and measuring the resulting current to determine its efficiency and other characteristics.

Why is a J-V scan important in perovskite solar cell research?

A J-V scan is important because it allows scientists to understand the behavior and performance of perovskite solar cells under different conditions. This information is crucial in developing more efficient and stable solar cell technologies.

How is a J-V scan performed?

To perform a J-V scan, a perovskite solar cell is connected to a source meter, which supplies a range of voltages to the cell. The resulting current is measured and recorded, and this data is used to plot a J-V curve. The scan can be performed under different light intensities or temperatures to study the cell's performance under varying conditions.

What information can be obtained from a J-V scan?

A J-V scan provides information on the open-circuit voltage, short-circuit current, fill factor, and efficiency of a perovskite solar cell. It also allows scientists to identify any defects or instabilities in the cell's performance.

What are some challenges in performing a J-V scan on perovskite solar cells?

Perovskite solar cells are prone to degradation and instability, which can affect the accuracy and reliability of J-V scan measurements. Additionally, the scan must be performed under controlled conditions, such as temperature and light intensity, to obtain accurate results. The measurement equipment used must also be precise and calibrated properly to ensure accurate data.

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