Wide-Bandgap Perovskite Solar Cell Technologies

Wide-bandgap perovskite solar cells (PSCs), typically employing absorbers with optical bandgaps in the range of 1.7–2.0 eV, have emerged as pivotal components for high-efficiency tandem photovoltaics and specialised applications such as semitransparent modules and indoor power generation. By tuning the halide composition and cation mixture, researchers can suppress sub-bandgap losses and engineer materials that deliver high open-circuit voltages while retaining strong visible absorption. Key challenges include photoinstability arising from light-induced halide segregation, non-radiative recombination at interfaces and within the bulk, and detrimental defect formation. Addressing these issues has led to a spectrum of strategies: cation engineering to enhance defect tolerance, additive-driven crystallisation control, two-dimensional/three-dimensional heterostructure formation for interfacial passivation, and advanced surface treatments to mitigate voltage deficits. The integration of wide-bandgap layers as the top cells in tandem architectures with silicon, copper indium gallium selenide (CIGS) or narrow-bandgap perovskites has propelled tandem device efficiencies beyond 28 per cent in laboratory settings. Concurrent developments in scalable deposition, interfacial layers and encapsulation techniques point towards commercially viable tandem modules. Globally, these advances hold promise for more efficient solar farms, building-integrated photovoltaics and niche indoor energy harvesting, underlining the broad impact of wide-bandgap perovskite technologies.

Research from Nature Portfolio

Recent studies have demonstrated that incorporating dipolar organic cations into mixed halide perovskites greatly enhances defect tolerance by healing deep trap states. This approach enabled wide-bandgap cells (1.65–1.74 eV) to achieve open-circuit voltages exceeding 1.22 V, fill factors above 80 per cent and stabilised efficiencies over 20 per cent. Density functional theory has elucidated how cation reorientation mitigates trap formation in bromide-rich matrices, offering a pathway to reduce voltage deficits in top cells for tandems.

A novel heterostructure strategy utilises a solution-mediated conversion of a thin three-dimensional perovskite overlayer into a two-dimensional phase atop 1.78 eV absorbers. This 2D/3D architecture effectively suppresses light-induced halide segregation, lowers non-radiative interfacial recombination and facilitates charge extraction. Monolithic all-perovskite tandems combining this wide-bandgap top cell with a thermal-stable narrow-bandgap bottom cell have reached 28.1 per cent stable power conversion efficiency under continuous illumination, retaining 90 per cent of initial performance after extended testing.

Wide-Bandgap Perovskite Solar Cell Technologies publication trend

The graph below shows the total number of articles in wide-bandgap perovskite solar cell technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Bandgap: The energy difference between a material’s valence and conduction bands, determining the range of absorbed photon energies.

Tandem Solar Cell: A multi-junction device that stacks absorbers with different bandgaps to harness a broader portion of the solar spectrum.

Halide Segregation: The phase separation of mixed halide components under illumination, causing local bandgap variation and performance degradation.

Defect Tolerance: A material’s ability to maintain carrier lifetimes and suppress non-radiative recombination despite the presence of structural defects.

Passivation: The process of neutralising or minimising defect states at surfaces or grain boundaries to reduce charge recombination.

References

1. Recent Advances in Wide-Bandgap Organic–Inorganic Halide Perovskite Solar Cells and Tandem Application. Nano-Micro Letters (2023).
2. Dipolar cations confer defect tolerance in wide-bandgap metal halide perovskites. Nature Communications (2018).
3. Heterojunction formed via 3D-to-2D perovskite conversion for photostable wide-bandgap perovskite solar cells. Nature Communications (2023).
4. Chloride‐Based Additive Engineering for Efficient and Stable Wide‐Bandgap Perovskite Solar Cells. Advanced Materials (2023).
5. Wide-Bandgap Metal Halide Perovskites for Tandem Solar Cells. ACS Energy Letters (2020).