Perovskite solar cell
A solar cell whose absorber is a metal-halide compound with the perovskite crystal structure, offering tunable bandgap, cheap processing and very fast efficiency gains.
Perovskite absorbers have the formula ABX3, where A is an organic or caesium cation (methylammonium, formamidinium, Cs), B is usually lead or tin and X a halide (iodide, bromide, chloride). Changing the halide mix tunes the bandgap from about 1.5 to 2.3 eV. Films can be deposited from solution or vapour at low temperature, potentially at a fraction of the energy needed for silicon wafers.
Single-junction efficiency rose from 3.8% in 2009 to about 26–27% in certified lab cells by 2025 (NREL Best Research-Cell Efficiency chart), a pace unmatched by any other PV material. The most promising route is the perovskite-silicon tandem: a wide-bandgap perovskite top cell (about 1.65–1.7 eV) above a silicon bottom cell. Certified tandem records reached about 34% in 2024 (LONGi), above the roughly 29.4% limit of silicon alone.
Barriers to commercialisation:
- Stability: degradation under moisture, heat, UV and ion migration; outdoor lifetimes still need to match 25–30 year warranties.
- Scaling: large-area module efficiency lags small cells.
- Lead content: requires encapsulation and end-of-life recovery.
Pilot lines in China, Europe and the US began shipping tandem and single-junction modules in small volumes in 2024–2025.
Related terms
All terms →- Photovoltaic effect
The generation of a voltage and electric current in a semiconductor junction when it absorbs photons with energy above the material bandgap.
- Heterojunction (HJT) solar cell
A cell that sandwiches an n-type crystalline silicon wafer between ultra-thin amorphous silicon layers, giving very high voltage and a low temperature coefficient.
- Thin-film solar
PV technologies that deposit absorber layers only a few micrometres thick onto glass, metal or plastic, mainly cadmium telluride, CIGS and amorphous silicon.
- Solar cell
A semiconductor device, usually a doped silicon wafer with metal contacts, that converts sunlight directly into direct-current electricity via the photovoltaic effect.
- Degradation rate
The gradual annual loss of a PV module power output over its life, typically around 0.5% per year for crystalline silicon.