How to fabricate high efficient perovskite solar cells?

How to fabricate high efficient perovskite solar cells?

My experience on Perovskites solar cells (PSCs) comes from IER-UNAM, where I had the opportunity to take a 1-week course with Dra. Hailin research group. Here, we developed some MAPbI3 Perovskite solar cells with regular n-i-p architecture. Due to the fabrication protocol they were following, we could develop PSCs of up to 12% in our first attempt.

Diploma - Development of Hybrid Perovskite Solar Cells - IER-UNAM, June 2019.
Workshop – Development of Hybrid Perovskite Solar Cells – IER-UNAM, June 2019.

Imagine how it feels to fabricate a device of 12% of conversión energy in your first week of experimental research. That is the magic of perovskite materials because it is easy to fabricate it following the research group’s protocols. In other words, they teach us some laboratory tips or, as they said, tricks that are well known only for those people who spend their time fabricating every layer evolved in the device.

A week ago, I searched for information related to the fabrication of high efficient perovskite solar cells (η >20%) to study the device architecture. In this research, I found a video from nanoGe Educational resource where Prof. Michael Saliba explains the importance of publishing detailed protocols to accelerate PSCs’ progress. This video helps me to understand how a highly efficient solar cell should be fabricated. Moreover, I found a perovskite expert who is active on social networks. Therefore, before you watch the video, let’s follow Prof. Michael Saliba on Twitter.

Following a Perovskite expert on Twitter

Why not? We are in 2021, and the world is highly connected; as I explained to you in my last post, the solar cell research community is on Twitter. Then, following the experts allow you to discover the latest publications or scholarship opportunities in our field.

Today I recommend to follow on twitter the next two accounts:

  • @miliba01 – Prof. Michael Saliba, Research on sustainable energy production & consumption
  • @SalibaLab – SalibaLab Research group exploring novel materials for solar cells and more for sustainable energy.

nanoGe Education Resource – Michael Saliba

If you are experienced in photovoltaics, you should watch the following video where Prof. Michael Saliba shows a resume of the research paper called “How to Make over 20% Efficient Perovskite Solar Cells in Regular (n–i–p) and Inverted (p–i–n) Architectures” .

How to Produce High Efficiency Perovskite Solar Cells by Michael Saliba

In the video, Prof. Michael tells us there are exponential possibilities (materials) for developing perovskite solar cells and every material could be fabricated by numerous deposition methods. Therefore, developing a high-efficiency perovskite solar cell depends on multiple processing steps which should be consistent every time they are made.

Why do we need protocols for the fabrication of solar cells?

Reproducibility is the key to push forward the development of perovskite solar cells. According to Prof. Michael Saliva, only a few groups in the world can reproduce η > 20% on a regular n-i-p perovskite architecture. It’s important to share protocols with the research community to level the knowledge among all the groups.

I had this kind of reproducibility problems in my experiences developing earth-abundant thin-film solar cells by chemical deposition. Reproducibility can be affected by each step of the development of the solar cell. Even the TCO cleaning should be done in a special way until the glass surface looks spotless.

In the words of a friend, “making a solar cell is like art“. Because a good solar cell highly depends on the skills of the person who fabricates it. In the video “How to Produce High Efficiency Perovskite Solar Cells by Michael Saliba” and the scientific paper, the authors explain how the following processing steps may influence the final conversion efficiency.

These are the lessons I am learning from the video to reproduce the high efficiency of a solar cell:

  • Fabrication: Depends on the solar cell maker skills. If the person has more time doing the same device, the efficiency tends to be more reproducible.
  • Chemicals: In order to avoid any mistake on the precursor’s solutions, we should not change from the provider so fast.
  • Precursor Preparation: It is highly recommended to follow the preparation protocol (formula and temperature condition).
  • Environment: Controlling the humidity of the room lab is a must to achieve reproducibility. Here, the problem arises because some materials are high hygroscopic. Then, using a glovebox with solvent extraction is essential.
  • Storage: There is some solution that needs to be prepared right before the deposition. And there are some which can be stored for weeks.

As you can see every step of the fabrication should be monitored also if there is a problem after each step. Then, the variation needs to be logged to correlate the improvements of the solar cell through time.

What do you think?

Please share your experience developing solar cells. If this post was helpful to you, consider beginning your own fabrication protocol.

If you like this post, don’t forget to share a cup of coffee and tell me what you would like to read about solar cells.

Bibliography

[1]
M. Saliba, J.-P. Correa-Baena, C.M. Wolff, M. Stolterfoht, N. Phung, S. Albrecht, D. Neher, A. Abate, How to Make over 20% Efficient Perovskite Solar Cells in Regular (n–i–p) and Inverted (p–i–n) Architectures, Chem. Mater. 30 (2018) 4193–4201. https://doi.org/10.1021/acs.chemmater.8b00136.

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