The world of solar energy is primed for transformation. Researchers are working tirelessly to create a new class of solar cells using materials with higher conversion efficiency than those found in panels today.

Silicon Solar Cells

Presently, the majority of solar panels in use are constructed from silicon, offering an efficiency rate of around 22%. This signifies that silicon panels can only transform approximately one-fifth of solar energy into electricity, as the material absorbs only a restricted range of sunlight wavelengths. Additionally, the production of silicon is costly and demands significant energy input.

Transforming to Perovskite Solar Cells

Introducing perovskite—a synthetic semiconductor with the capability to generate significantly more solar energy than silicon, and at a reduced production expense.

On Saturday, CleanTechnica reported that University of Colorado Boulder researchers, together with their international collaborators, unveiled a new method for manufacturing perovskite solar cells. This is an important step towards the commercial viability of what many consider to be the next generation of solar technology.

Michael McGehee, a professor in the Department of Chemical and Biological Engineering and a fellow at CU Boulder’s Renewable & Sustainable Energy Institute, suggested that perovskites could be a significant breakthrough.

Researchers have been experimenting with stacking perovskite solar cells on traditional silicon cells to create tandem cells, potentially increasing panel efficiency by over 50% as each material absorbs different parts of the sun's spectrum.

McGehee highlighted the ongoing shift towards electrification and the necessity to enhance solar cells' efficiency to accommodate this transition. However, a significant obstacle in scaling up perovskite solar cells commercially is the coating process, which currently requires a nitrogen-filled environment to prevent oxidation. 

Additive to Enhance the Solar Cells’ Stability

McGehee and his team discovered that adding dimethylammonium formate (DMAFo) to the perovskite solution before coating can prevent oxidation, allowing for coating in ambient air. This breakthrough enables perovskite cells to achieve efficiencies of nearly 25%, comparable to the current record of 26%, without the need for a nitrogen-filled environment.

Commercial silicon panels typically maintain around 80% of their efficiency after 25 years, losing approximately 1% of efficiency annually. Perovskite cells, however, degrade faster due to their reactivity in air.

The study demonstrated that perovskite cells with DMAFo retained 90% of their efficiency after exposure to simulated sunlight for 700 hours, compared to rapid degradation in cells without DMAFo after only 300 hours.

While these results are promising, longer-term testing is necessary to assess their stability over time. Michael McGehee emphasized that although it's premature to claim parity with silicon panels' stability, the findings indicate a positive trajectory.

Commercial of the Perovskite Solar Cells

The research advances the commercialization of perovskite solar cells, while McGehee's team is actively developing tandem cells with an operational efficiency exceeding 30%, matching the longevity of silicon panels.

Heading the U.S. partnership TEAMUP, they received $9 million from the U.S. Department of Energy to create stable tandem perovskites for real-world use, aiming to outperform traditional silicon panels over a 25-year span.

These more efficient and potentially more affordable tandem cells could find diverse applications, including on electric vehicle roofs, providing up to 15 to 25 miles of daily range.

After a decade of research, engineers have developed perovskite cells with efficiency levels comparable to silicon cells, a technology that has been around for 70 years. McGehee expressed confidence in perovskites' potential, stating that successful tandem cell development could lead them to dominate the solar market as the next generation of solar cells.