Tech Insights

Tandem Solar Cells Are Breaking Records

September 28, 2023 by Ellie Gabel

Breakthroughs in tandem solar cell technology are making solar generation more efficient and adaptable for multiple uses

Tandem solar cells are photovoltaic devices that stack multiple solar cell materials on top of each other to boost energy conversion efficiency. These cells are pivotal in engineering due to their ability to harness more sunlight and generate increased electrical output compared to traditional cells.


Researchers at King Abdullah University of Science and Technology have developed tandem solar cells made of perovskite and silicon.

Researchers at King Abdullah University of Science and Technology have developed tandem solar cells made of perovskite and silicon. Image used courtesy of KAUST 


Recent breakthroughs in tandem solar cell technology have been game changers for engineers, promising greater energy production while using less space. These advancements have fueled excitement among industry enthusiasts as they pave the way for more efficient and sustainable energy solutions.


Understanding Tandem Solar Cells

Tandem or multi-junction solar cells work by combining different solar cell panels on top of one another. Each layer absorbs a specific range of sunlight, allowing the cell to capture a broader spectrum of light and convert it into electricity. This approach significantly improves efficiency, as the solar cell can generate more power from the same amount of sunlight.


An example of a solar cell using perovskite.

An example of a solar cell using perovskite. Image used courtesy of NREL


Engineers are highly interested in enhancing solar cell efficiency because it directly impacts the effectiveness and sustainability of solar energy systems. Higher efficiency means producing more electricity from sunlight and making solar power more practical and cost effective for various applications. This drive for efficiency aligns with engineers’ goals to develop cleaner and more efficient energy solutions to combat climate change and meet growing energy demands.


Engineering the Tandem Solar Cells

Creating tandem solar cells involves a meticulous engineering process. First, engineers select suitable semiconductor materials with unique light-absorbing properties and carefully layer them. This stacking ensures each layer captures a specific portion of sunlight.

Innovative techniques like perovskite-silicon tandem cells have gained popularity for their potential to enhance efficiency further. At the King Abdullah University of Science and Technology (KAUST), researchers recently broke records when they created a tandem solar cell with 33.7% power conversion efficiency.

Additionally, emerging materials such as perovskites and organic compounds contribute to the innovation in tandem solar cell design, promising even more efficient and cost-effective solar energy solutions.


Solar Cell Specifications and Advancements

KAUST’s cutting-edge solar cells boast impressive technical specifications that set them apart from previous technology:

  • Efficiency: These cells achieve over 30% power conversion—a significant improvement over traditional solar cells, which typically operate at around 20% solar efficiency. This means they can convert a more substantial portion of sunlight into electricity.

  • Tandem structure: They comprise multiple layers of carefully constructed materials, allowing them to capture a broader spectrum of the sun.

  • Bandgap engineering: Engineers meticulously engineer the bandgap of each layer to optimize light absorption, ensuring they efficiently absorb different parts of the solar spectrum.

  • Stability: Recent advancements have also addressed stability issues common in earlier tandem cells. New materials and encapsulation techniques enhance their durability, making them more reliable.

  • Flexibility: Some variants of these cells are flexible, enabling their use in a broader range of applications, including curved surfaces or portable devices.

  • Cost reduction: Engineers are working on scalable manufacturing methods, potentially reducing production costs and making these cells more economically viable.

  • Environmental impact: These cells often use eco-friendly materials, contributing to sustainability goals.


Tandem Solar Cell Advantages and Disadvantages

Tandem solar cells offer a plethora of advantages for engineers. Their standout feature is significantly higher efficiency. This translates to a remarkable increase in electricity production from the same amount of sunlight.

Further, the long-term cost savings are substantial. In 2021, the average monthly consumption of businesses amounted to 5,795 kilowatt-hours or an electric bill of $650. The enhanced efficiency of tandem cells maximizes energy production and reduces installation and maintenance costs. It particularly appeals to engineers and project managers looking to optimize performance and budget.


Advancements in solar technology have led to steadily decreasing costs in residential, commercial, and utility use.

Advancements in solar technology have led to steadily decreasing costs in residential, commercial, and utility use. Image used courtesy of NREL


In an era focused on sustainability, tandem cells also substantially contribute to reducing greenhouse gas emissions and mitigating climate change. Their ability to harness more solar energy aligns perfectly with engineering’s commitment to innovative, eco-friendly solutions.

While tandem solar cells hold tremendous promise, engineers must consider possible drawbacks and limitations. Manufacturing these cells can be intricate and costly due to their complex layering and precise engineering requirements. The initial investment may be more expensive compared to traditional solar cells. Engineers must weigh this against the long-term benefits to determine the feasibility of specific projects.

Another consideration is the sensitivity of certain tandem cell materials to environmental factors. Moisture and heat can affect their performance, necessitating improved encapsulation techniques. Ensuring the long-term stability of these materials remains a challenge, impacting the overall durability of the cells.


Tandem Solar Cell Applications

Industry enthusiasts have ample reasons to be excited about the recent developments in tandem solar cells. These advancements offer them many opportunities and align with their core objectives in multiple ways.

Practical applications abound for engineers in various industries:

  • Renewable energy: In this sector, tandem solar cells are a huge advancement. They enable the efficient generation of electricity from sunlight, making them an ideal choice for solar farms and reducing the world’s reliance on fossil fuels.

  • Electronics: Engineers working on portable devices can integrate flexible tandem cells into products like smartphones, wearables, and remote sensors. It empowers these devices to operate longer in the field, reducing the need for frequent charging.

  • Transportation: Manufacturers can integrate tandem solar cells into electric vehicles, extending their range by harnessing solar energy from the vehicle’s surface.

  • Architecture: Those involved in building design can incorporate transparent tandem cells into windows and facades, turning structures into energy generators and reducing reliance on grid power.


NASA is installing solar cells with perovskite on satellites and other technology designed for use in space.

NASA is installing solar cells with perovskite on satellites and other technology designed for use in space. Image used courtesy of NREL


  • Aerospace: Engineers in this sector can use it for satellites, providing a sustainable power source for extended missions in space.

  • Emerging technologies: As technologies like the Internet of Things and autonomous systems continue to grow, engineers can explore how tandem solar cells can power them, offering greater sustainability and autonomy.


The Future of Tandem Solar Cells

These tandem technologies are often integral to broader sustainable energy initiatives aimed at addressing global environmental challenges. Researchers working on this frequently collaborate with organizations, research networks, and institutions to accelerate progress and maximize their impact.

Tandem solar cells interconnect closely with broader sustainable energy initiatives, and engineers play a pivotal role in these efforts. Collaborations and research networks drive innovation and bring people closer to a cleaner and more sustainable future. Engineers can actively participate in these initiatives to contribute to global sustainability goals.