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Perovskites are a class of materials with a specific crystal structure, the same arrangement of atoms originally found in the mineral perovskite (calcium titanium oxide). This structure can accommodate many different combinations of elements, creating a vast family of materials with diverse properties. In the energy context, "perovskites" typically refers to hybrid organic-inorganic metal halide perovskites, materials combining organic molecules, metal ions (often lead), and halide ions (chloride, bromide, or iodide) in the perovskite crystal structure.

These materials exhibit remarkable optoelectronic properties that make them exceptionally promising for solar cells and other light-based applications. They absorb light strongly across the visible spectrum, convert absorbed photons to electrical charge efficiently, and transport that charge effectively, which are all essential requirements for high-performance solar cells. Critically, perovskites can be fabricated using low-cost, solution-based processes, basically printing or coating them from liquid precursors at low temperatures, rather than the high-temperature, vacuum-based processing required for silicon solar cells. This has significant implications in the reduction of manufacturing costs, and the affordability of the technology.

Perovskite solar cells have achieved unprecedented efficiency improvements in an extremely short timeframe. The first perovskite solar cell, demonstrated in 2009, converted less than 4% of sunlight to electricity. By 2025, laboratory devices exceed 26% efficiency, rivaling the best commercial silicon solar cells and approaching the theoretical efficiency limit for single-junction cells. This progress, achieved in just 15 years compared to the 70+ years of silicon development, demonstrates the potential of these materials.

However, significant challenges remain before perovskite solar cells can achieve widespread commercial deployment. RASEI research addresses these challenges across multiple fronts.

One of the most critical challenges facing perovskite solar cells is long-term stability. Many perovskite compositions degrade when exposed to moisture, oxygen, heat, or prolonged light exposure, not great for something we want to install outside! Commercial solar panels must last 25-30 years outdoors. RASEI researchers work to understand the fundamental mechanisms of perovskite degradation at the molecular level, develop perovskite compositions that are inherently more stable, engineer protective encapsulation strategies, and design device architectures that minimize degradation pathways. Even small improvements in stability dramatically affect commercial viability.

Laboratory perovskite solar cells are typically tiny, currently often less than 1 cm² area. Scaling to commercial panel sizes (1-2 m²) while maintaining efficiency and uniformity presents substantial challenges. Solution-processing methods that work well at small scale may produce non-uniform films at large scale. RASEI research addresses scalable fabrication techniques, understanding how processing parameters affect film quality over larger areas, developing methods for reproducible manufacturing, and identifying defects or inconsistencies that limit large-area device performance.

One of the most promising near-term applications for perovskites is tandem solar cells, effectively devices that stack a perovskite cell on top of a silicon cell. Silicon efficiently converts red and infrared light but wastes higher-energy blue and green photons as heat. Perovskites can be tuned to efficiently capture those higher-energy photons while remaining transparent to the red/infrared light that silicon absorbs. This combination can achieve efficiencies exceeding 33%, well beyond what either material can achieve individually. RASEI researchers develop perovskites optimized for tandem configurations, engineer interfaces between perovskite and silicon layers, and address manufacturing issues that integrate these different materials. Tandem cells represent a pathway to introduce perovskite technology into markets by enhancing existing silicon infrastructure rather than replacing it.

Beyond solar: optoelectronic applications. Perovskites' exceptional light-interaction properties extend beyond photovoltaics. RASEI research explores:

Light-emitting diodes (LEDs): Perovskites can emit bright, pure-color light with tunable wavelength based on composition. Perovskite LEDs could enable more efficient, vivid displays and lighting.

Lasers: The same properties that make perovskites good light emitters enable low-threshold lasing, providing devices capable of producing coherent light with minimal input energy. Applications include communications, sensing, and integrated photonics.

Photodetectors: Perovskites' strong light absorption and fast charge transport make them excellent photodetectors for cameras, sensors, and imaging applications across visible and near-infrared wavelengths.

An emerging area of RASEI research involves chiral hybrid perovskites, structures that lack mirror symmetry, like a left hand versus a right hand. These materials can exhibit the chirality-induced spin selectivity (CISS) effect, where electron transport depends on electron spin orientation. This effect could enable new approaches to controlling charge and spin in devices, with applications in more efficient solar cells (by reducing recombination losses), spintronics (devices that use electron spin for information processing), and quantum technologies. This represents frontier research connecting fundamental physics with practical device applications.

A defining feature of RASEI's perovskite research is the emphasis on fundamental understanding, where we are not just making better devices, but understanding at the molecular and atomic level why certain compositions, structures, and processing methods work better than others. Advanced characterization techniques and computational simulations reveal how atoms are arranged, where defects occur, how charges move through the material, and how degradation begins. This deep understanding enables rational design of improved materials rather than trial-and-error experimentation and optimization.

Perovskites represent one of the most promising material platforms for next-generation energy technologies though realizing that promise requires solving substantial challenges in stability and scalable manufacturing. RASEI's comprehensive approach, that includes fundamental materials science, device engineering, and manufacturing processes, provides teams ready to addresses these challenges across the full development pipeline, working toward perovskite technologies that can deliver on their remarkable potential in real-world applications.