Notes on Perovskite Solar Cells

Introduction

• Perovskite materials are considered game changers in solar photovoltaics.
• A recent paper (June 2022) claims to have developed a perovskite solar cell with a commercially viable lifespan.

What is Perovskite?

• Exists as a mineral made from calcium, titanium, and oxygen in a crystalline structure.
• Named after geologist Lev Perovsky, discovered in the Ural mountains in the 19th century.
• Developed into a class of materials referred to as ABX3 structures (A & B = cations, X = anion).

Working Principle of Photovoltaic Panels

• Traditional panels use silicon as a semiconductor to absorb solar energy.
• Silicon is sandwiched between two electrodes (positive and negative).
• Doping silicon with phosphorus (top) and boron (bottom) creates free electrons and holes.
• Electrons move towards the positive electrode; holes move towards the negative electrode to generate electricity.
• Defects in silicon reduce efficiency, requiring high-energy processes to eliminate them.

Advantages of Perovskite Solar Cells

• Do not require phonons to liberate electrons, allowing for thin film manufacturing.
• Wider range of light absorption compared to silicon.
• More tolerant to defects, reducing production costs and energy demands.
• Can be synthesized from inexpensive materials.
• Efficiency improved from 3% (10 years ago) to 29% (recent tests).

Challenges with Perovskite Solar Cells

• Historically fragile and prone to rapid degradation under light and heat.
• Recent advancements at Princeton University focus on improving durability.

Recent Research Developments

• Princeton researchers layered cesium lead iodide (chlorine) on perovskite to enhance durability and light absorption.
• New long-term testing method developed to assess performance.
• Simulated aging through high intensity light and heat, revealing:
  • Over 80% peak efficiency maintained for 5 years at 35°C.
  • Equivalent to 30 years of outdoor operation in areas like New Jersey.

Future of Perovskite Solar Cells

• Likely to complement silicon cells rather than replace them.
• Overcoming the Shockley-Queisser limit by adjusting the band gap of materials could enhance efficiency.
• Potential for tandem or multi-junction cells to exceed 40% efficiency.
• Applications could expand to diverse, non-uniform surfaces, including agricultural and water bodies.

Conclusion

• Rapid advancements in perovskite technology lead towards more efficient and affordable solar panels.
• Engagement encouraged from viewers to discuss solar adoption and insights.
• Acknowledgment of Patreon supporters and invitation to support the channel.