A perovskite solar cell (PSC) is a type of solar cell that includes a perovskite-structured compound, most commonly a hybrid organic–inorganic lead or tin halide-based material as the light-harvesting active layer. Perovskite materials, such as methylammonium lead halides and the all-inorganic cesium lead halide, are cheap to produce and simple to manufacture.
Solar-cell efficiencies of laboratory-scale devices using these materials have increased from 3.8% in 2009 to 27% in 2025 in single-junction architectures, and, in silicon-based tandem cells, to 34.85%, exceeding the maximum efficiency achieved in single-junction silicon solar cells. Perovskite solar cells have therefore been the fastest-advancing solar technology . With the potential of achieving even higher efficiencies and very low production costs, perovskite solar cells have become commercially attractive. Core problems and research subjects include their long-term stability, high sensitivity to moisture, and toxicity if lead is used. Managing toxic lead in PSCs is essential, as exposure presents significant health risks, including neurological disorders. Because PSCs are an emerging technology, lead toxicity remains a major hurdle to widespread adoption and commercialization.
Advantages The raw materials used and the possible fabrication methods (such as various printing techniques) are both low-cost. Their high absorption coefficient enables ultrathin films of around 500 nm to absorb the complete visible solar spectrum. These features combined result in the ability to create low-cost, high-efficiency, thin, lightweight and flexible solar modules. Perovskite solar cells have found use in powering prototypes of low-power wireless electronics for ambient-powered Internet of things applications, and may help mitigate climate change.
Perovskite cells also possess many optoelectrical properties that benefit their use in solar cells. For example, the exciton binding energy is small. This allows electron holes and electrons to be easily separated upon the absorption of a photon. Moreover, the long diffusion distance of the charge carrier and the high diffusivity – the rate of diffusion – allow the charge carriers to travel long distances within the perovskite solar cell, which improves the chance of it to be absorbed and converted to power. Lastly, perovskite cells are characterized by wide absorption ranges and high absorption coefficients, which further increase the power efficiency of the solar cell by increasing the range of photon energies that are absorbed.
Perovskite solar cells (PSCs) are considered strong candidates in the photovoltaic sector due to their low energy payback time (EPBT), low levelized cost of electricity (LCOE), and rapidly increasing power conversion efficiencies (PCEs). In under two decades, PSCs have reached laboratory efficiencies of 27%, a milestone that monocrystalline silicon required more than 50 years to achieve, owing largely to perovskites' defect tolerance, low recombination losses, and long carrier diffusion lengths. Perovskite materials can also be combined with other photovoltaic technologies in tandem architectures, with perovskite–silicon two-terminal devices recently achieving a record PCE of 34.6%, underscoring their potential for next-generation high-efficiency solar cells.
Materials used
The name "perovskite solar cell" refers to the ABX3 crystal structure of the absorber materials, called perovskite structure, where A and B are cations and X is an anion. A cations with radii between 1.60 Å and 2.50 Å have been found to form perovskite structures. The most commonly studied perovskite absorber is methylammonium lead trihalide (CH3NH3PbX3, where X is a halogen ion such as iodide, bromide, or chloride), which has an optical bandgap between ~1.55 and 2.3 eV, depending on halide content. Formamidinium lead trihalide (H2NCHNH2PbX3) has also shown promise, with bandgaps between 1.48 and 2.2 eV. The perovskite composition H₂NCHNH₂PbI₃ and its favorable bandgap were first reported in the seminal work of Stoumpos, Malliakas, and Kanatzidis on semiconducting tin and lead iodide perovskites, and compositional variants of this system now form the basis of the most efficient perovskite solar cells known today.Semiconducting tin and lead iodide perovskites with organic cations: phase transitions, high mobilities, and near-infrared photoluminescent properties CC Stoumpos, CD Malliakas, MG Kanatzidis Inorganic chemistry 2013, 52 (15), 9019-9038 Its minimum bandgap is closer to the optimal for a single-junction cell than methylammonium lead trihalide, so it should be capable of higher efficiencies. The first use of perovskite in a solid-state solar cell was in a dye-sensitized cell using CsSnI3 as a p-type hole transport layer and absorber. In this all solid state architecture, CsSnI₃ replaced the liquid electrolyte and provided both efficient hole conduction and additional solar light absorption extending into the red and near infrared. This work established that a three dimensional halide perovskite could function as an active semiconducting component in a solid-state device at high efficiency, and it laid essential groundwork for the modern generation of halide perovskite solar cells. A common concern is the inclusion of lead as a component of perovskite materials; solar cells composed from tin-based perovskite absorbers such as CH3NH3SnI3 have also been reported, though with lower power-conversion efficiencies.
Shockley–Queisser limit Solar cell efficiency is limited by the Shockley–Queisser limit. This calculated limit sets the maximum theoretical efficiency of a solar cell using a single junction with no other loss aside from radiative recombination in the solar cell. Based on the AM1.5G global solar spectra, the maximum power conversion efficiency is correlated to a respective bandgap, forming a parabolic relationship.
This limit is described by the equation
Where
and u is the ultimate efficiency factor, and v is the ratio of open circuit voltage Vop to band-gap voltage Vg, and m is the impedance matching factor, and Vc is the thermal voltage, and Vs is the voltage equivalent of the temperature of the Sun.
The most efficient bandgap is found to be at 1.34 eV, with a maximum power conversion efficiency (PCE) of 33.7%. Reaching this ideal bandgap energy can be difficult, but utilizing tunable perovskite solar cells allows for the flexibility to match this value. Further experimenting with multijunction solar cells allow for the Shockley-Queisser limit to be surpassed, expanding to allow photons of a broader wavelength range to be absorbed and converted, without increasing thermalisation loss.
The actual band gap for formamidinium (FA) lead trihalide can be tuned as low as 1.48 eV, which is closer to the ideal bandgap energy of 1.34 eV for maximum power-conversion efficiency single junction solar cells, predicted by the Shockley–Queisser Limit. The 1.3 eV bandgap energy has been successfully achieved with the hybrid cell, which has a tunable bandgap energy (Eg) from 1.24 – 1.41 eV.
Multi-junction solar cells Multi-junction solar cells are capable of a higher power conversion efficiency (PCE), increasing the threshold beyond the thermodynamic maximum set by the Shockley-Queisser limit for single junction cells. By having multiple bandgaps in a single cell, it prevents the loss of photons above or below the band gap energy of a single junction solar cell. In tandem (double) junction solar cells, PCE of 31.1% has been recorded, increasing to 37.9% for triple junction and 38.8% for quadruple junction solar cells. However, the metal organic chemical vapor deposition (mocvd) process needed to synthesize lattice-matched and crystalline solar cells with more than one junction is very expensive, making it a less than ideal candidate for widespread use.
Perovskite semiconductors offer an option that has the potential to rival the efficiency of multi-junction solar cells but can be synthesized under more common conditions at a greatly reduced cost. Rivalling the double, triple, and quadruple junction solar cells mentioned above, are all-perovskite tandem cells with a max PCE of 31.9%, all-perovskite triple-junction cell reaching 33.1%, and the perovskite-Si triple-junction cell, reaching an efficiency of 35.3%. These multi-junction perovskite solar cells, in addition to being available for cost-effective synthesis, also maintain high PCE under varying weather extremes, making them utilizable worldwide.
Perovskite–silicon tandem solar cells (PSTSCs) are an emerging class of multi-junction photovoltaic devices. These cells combine a conventional silicon sub-cell with an upper perovskite absorber layer to achieve broader spectral utilization. Silicon has a band gap of approximately 1.12 eV, while the perovskite band gap can be tuned between about 1.6 and 1.8 eV, enabling theoretical power-conversion efficiencies of up to 45.3% for perovskite–silicon tandems.
PSTSCs are commonly categorized by the number of electrical terminals used to interconnect the sub-cells. Two-terminal (2T) designs place the perovskite and silicon cells in series, joined by an interconnection layer. This architecture is relatively low-cost but requires strict current matching between the sub-cells; any mismatch results in current losses, and it constrains the perovskite band-gap selection to the illumination and the silicon cell's characteristics .
Four-terminal (4T) tandems physically stack the two sub-cells but operate them independently, eliminating current-matching constraints and allowing each cell to be optimized separately. Three-terminal (3T) devices represent an intermediate architecture: the sub-cells contribute separate currents but their voltages add, removing the need for current matching while using fewer terminals than a 4T design.
Although perovskite–silicon tandem cells have demonstrated rapid efficiency gains, large-scale commercialization remains limited. Key challenges include high materials and processing costs, limited manufacturing infrastructure, and reduced long-term stability relative to conventional single-junction silicon modules. Ongoing advances in perovskite chemistry, device architecture, and encapsulation may enable PSTSCs to become a high-efficiency option for applications where maximizing power per unit area is critical.
Chiral ligands Utilizing organic chiral ligands shows promise for increasing the maximum power conversion efficiency for halide perovskite solar cells, when utilized correctly. Chirality can be produced in inorganic semiconductors by enantiomeric distortions near the surface of the lattice, electronic coupling between the substrate and a chiral ligand, assembly into a chiral secondary structure, or chiral surface defects. By attaching a chiral phenylethylamine ligand to an achiral lead bromide perovskite nanoplatelet, a chiral inorganic-organic perovskite is formed. Inspection of the inorganic-organic perovskite via Circular Dichroism (CD) spectroscopy, reveals two regions. One represents the charge transfer between the ligand and the nanoplatelet (300-350 nm), and the other represents the excitonic absorption maximum of the perovskite. Evidence of charge transfer in these systems shows promise for increasing power conversion efficiency in perovskite solar cells.
Inorganic perovskites