Tech Insights

4 Breakthroughs in Perovskite Solar Cell Research

May 18, 2023 by Emily Newton

Research breakthroughs in perovskite solar cells are generating excitement about improved efficiencies and other possibilities.

Perovskite solar cells have become a much-discussed topic in the scientific and energy communities due to their substantial efficiency advantages. Here are four recent breakthroughs generating excitement.

 

solar cells

Solar cells are highly researched. Image used courtesy of Pixabay
 

Single-Step Coating Process for Better Commercial Potential

The typical way to manufacture perovskite solar cells requires a layer-by-layer approach that restricts the opportunities for scaling and widespread production. However, researchers from the City University of Hong Kong and the National Renewable Energy Laboratory created a one-step process for coating the panels.

This investigation revealed adding particular phosphonic or carboxylic to perovskite precursor solutions would cause the solution to assemble itself on the indium tin oxide substrate, creating a monolayer that makes a tremendous hole-selective contact while the perovskite crystallization occurs.

Dr. Zhu Zonglong–who co-led the research–explained the team devised an option for processing the hole-selective contact and perovskite layer without two dedicated steps. That approach achieved 24.5% efficiency and made the inverted perovskite solar cells exceptionally stable. The cells also kept more than 90% of their initial efficiency even after 1,200 operating hours of non-stop illumination at the maximum power point.

 

Novel Additives for Perovskite Films

One enduring goal is to make perovskite solar cells durable enough for long-term use and environmental exposure. A research team from several Korean universities created new perovskite film treatment additives, resulting in highly efficient and stable solar cells.

People are increasingly interested in solar panels. Business leaders like the sustainability and energy-savings aspects, but solar panels will only remain attractive if consumers feel confident they will last.

 

solar panels

Researchers are examining how to make solar panels last. Image used courtesy of Pixabay
 

This innovation targets two downsides–perovskite cells are highly susceptible to surface defects and not sufficiently moisture-resistant. Both negatively affect solar cells’ energy conversion efficiency. The conventional surface-treatment method is to dissolve the passivating material in a solvent. The solvent vapor can solidify the additive, making it less able to remove defects.

This group selected an additive called alkylammonium formats (AAFos). It has components that remain liquid at relatively low temperatures. A short thermal treatment made the AAFos transform from a solid to liquid, eliminating surface defects. The AAFos also improved moisture resistance, creating a wetness barrier for the perovskite layer.

A widespread myth is since solar power is typically about 15% to 20% efficient, it is not a suitable renewable energy source. However, the sun creates abundant energy for solar panels, and research is ongoing to get even better results. This team got a 25% power conversion efficiency from an area of active perovskite cells.

 

Slot-Die-Coating Method for Faster Industrial Production 

People are particularly interested in solar cells made from metal halide perovskites because these options have a relatively low production cost and are very energy efficient. Now, a team from Helmholtz-Zentrum Berlin is analyzing the best precursor ink composition to use slot die-coating for producing high-quality, thin perovskite films.

One issue the team wanted to overcome was how coating halide perovskite layers on large surfaces could lead to unwanted variations. Thus, they worked with different ink viscosities to minimize such outcomes. The best options achieved a 22.3% efficiency in the lab.

The team then ran a year-long outdoor test on the optimized cells. It showed the efficiency was nearly unchanged during winter and spring and dropped slightly during the summer. Those results in a real-world setting will give this group and others helpful takeaways that could improve the further development of perovskite solar cells.

 

Machine Learning to Find New Materials for Perovskite Solar Cells

Material selection is vital to solar cell engineering — especially when working with perovskites, which are not yet as commercially available as other options. A team from the engineering department at the University of California-Davis turned their attention to hybrid perovskites for solar applications. They wondered if machine learning could help them find suitable materials faster.

Marina Leite — the senior author of a paper about the matter — explained how the possible chemical combinations for perovskite cells are enormous, and people must consider how it would perform in certain environmental conditions, too.

The first step in this machine learning-based application was to build an automated, high-throughput system to calculate the photoluminescence efficiency of five perovskite films. The team collected more than 7,000 measurements during a sunny week in Sacramento. That exercise gave them enough data to make a training set.

They used it to train three machine learning algorithms, then compared the predictions of each to results measured in the lab. Doing that allowed them to see which one was most accurate. The outcomes indicated one was a 90% match to conditions observed during a 50-plus-hour window.

Eventually, the team wants to expand their experiments and apply this approach by testing how the cells behave with environmental influencers. They also believe they could use machine learning to examine the likely performance of full solar power systems beyond just the perovskite cells.

 

Exciting Times for Perovskite Solar Cell Research

These four examples show why people have much to look forward to regarding progress in using perovskite solar cells. Each breakthrough will give scientists valuable information to guide their future efforts and share learnings with colleagues. Then, the solar energy sector will move forward, making clean, renewable power more accessible and feasible for everyone.