Advanced Inorganic Perovskite Solar Cell Technologies

All-inorganic perovskite solar cells have emerged as a leading class of photovoltaic devices owing to their exceptional thermal stability, tunable bandgaps and low fabrication costs. By replacing organic cations with inorganic alternatives such as caesium, these materials resist phase degradation at elevated temperatures and exhibit improved shelf life under real-world conditions. Key technical advances have focused on controlling crystallisation dynamics, defect passivation and energy-level alignment at multiple interfaces. Strategies such as surface sulfidation, dimensionality engineering with two-dimensional passivating layers and the creation of phase heterojunctions have boosted power conversion efficiencies beyond 20 per cent while enhancing operational stability. Innovations in additive doping—incorporating elements like cadmium—and ambient air processing methods have further simplified manufacturing and reduced reliance on inert atmospheres. As a result, all-inorganic perovskites are now poised for applications ranging from building-integrated photovoltaics to tandem architectures that pair with silicon or CIGS bottom cells, signalling a major step towards sustainable, high-performance solar energy solutions.

Research from Nature Portfolio

Recent studies have demonstrated that constructing a phase heterojunction between two polymorphs of the same inorganic perovskite can substantially enhance device performance. By interfacing γ-CsPbI3 with β-CsPbI3, researchers achieved a power conversion efficiency of 20.1 per cent. This improvement arises from efficient passivation of the smaller-bandgap phase by the larger-bandgap polymorph and an increase in built-in potential due to optimal energetic alignment across the junction. Foundational work employing a small Lewis base molecule to passivate defect sites on caesium–lead halide perovskite films resulted in champion inverted devices with efficiencies above 16 per cent and certified photostability. The nitrile functional groups in the passivating molecule bind to under-coordinated lead ions, suppress non-radiative recombination and raise the open-circuit voltage to over 1.16 V.

Advanced Inorganic Perovskite Solar Cell Technologies publication trend

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

Technical terms

Perovskite: A crystalline structure of formula ABX3, where A is a monovalent cation (here caesium), B a metal (lead) and X a halide, noted for exceptional optoelectronic properties.

Phase heterojunction: Interface formed between two polymorphs or phases of the same perovskite composition, engineered to improve charge separation and passivation.

Passivation: Chemical treatment of the perovskite surface or grain boundaries to reduce defect density and suppress non-radiative recombination.

Non-radiative recombination: Energy loss process in which excited electrons and holes recombine without emitting photons, lowering device voltage and efficiency.

Band bending: Variation in energy levels at an interface that facilitates directional charge-carrier separation and extraction.

Hole transport layer (HTL): Material layer that selectively extracts positive charge carriers (holes) from the perovskite absorber to the electrode.

Gradient heterojunction: Engineered interfacial region with gradually varying energy levels, designed to guide charge carriers and minimise recombination losses.

References

1. Perovskite phase heterojunction solar cells. Nature Energy (2022).
2. Highly efficient all-inorganic perovskite solar cells with suppressed non-radiative recombination by a Lewis base. Nature Communications (2020).
3. Surface sulfidation constructing gradient heterojunctions for high‐efficiency (approaching 18%) HTL‐free carbon‐based inorganic perovskite solar cells. Carbon Energy (2024).
4. Unveiling the Potential of Ambient Air Annealing for Highly Efficient Inorganic CsPbI3 Perovskite Solar Cells. Journal of the American Chemical Society (2024).
5. Stabilization of Inorganic Perovskite Solar Cells with a 2D Dion–Jacobson Passivating Layer. Advanced Materials (2023).
6. Simultaneous Lattice Engineering and Defect Control via Cadmium Incorporation for High‐Performance Inorganic Perovskite Solar Cells. Advanced Science (2022).