Perovskite tandem solar cells are emerging as one of the most promising innovations in renewable energy. As traditional silicon panels approach their practical efficiency ceiling, researchers are turning to tandem architectures to capture a broader portion of the solar spectrum. By combining a perovskite top layer with a silicon bottom cell, these advanced devices absorb high-energy and low-energy photons separately, reducing losses that limit single-junction technologies.
Conventional silicon cells typically achieve efficiencies around 26–27% in real-world conditions and face a theoretical ceiling near 32%, known as the Shockley–Queisser limit. Tandem designs overcome this barrier by stacking materials with complementary bandgaps. The perovskite layer, which can be chemically tuned to absorb specific wavelengths, captures blue and green light, while silicon absorbs red and infrared light. This configuration significantly reduces thermal and optical losses.
Recent laboratory milestones highlight the rapid progress of this technology. Perovskite-silicon tandem cells have surpassed 34% efficiency under controlled conditions, a remarkable improvement over standard silicon devices. Importantly, these gains are no longer limited to small prototypes—commercial-scale cells are steadily improving, bringing the technology closer to widespread adoption.
Two primary configurations dominate development: two-terminal (2T) and four-terminal (4T) designs. The 2T structure connects subcells in series, requiring precise current matching, while the 4T approach allows independent operation of each layer, offering greater flexibility but increased manufacturing complexity.
Despite impressive progress, challenges remain. Stability under heat, moisture, and UV exposure continues to be a concern, though advances in encapsulation, interface engineering, and material composition are extending device lifetimes. Scaling production while maintaining quality is another key hurdle.
With continued research and industrial investment, perovskite tandem solar cells could significantly lower the cost per watt of solar electricity. Their higher efficiency and compatibility with existing silicon manufacturing make them strong candidates to shape the next generation of photovoltaic technology.