Hybrid Perovskite Photovoltaics Photochromic materials enable dynamic stabilization of perovskite solar cells, such as during the simulated day-night cycles, which is the result of their reversible transformation in response to light, setting the stage for smart nature-inspired photovoltaic systems and technologies in the future. More details can be found in article number 2420143 by Jovana V. Milić and co-workers.

The application of perovskite photovoltaics is hampered by issues related to the operational stability upon exposure to external stimuli, such as voltage bias and light. The dynamic control of the properties of perovskite materials in response to light could ensure the durability of perovskite solar cells, which is especially critical at the interface with charge-extraction layers. We have applied a functionalized photochromic material based on spiro-indoline naphthoxazine at the interface with hole-transport layers in the corresponding perovskite solar cells with the aim of stabilizing them in response to voltage bias and light. We demonstrate photoinduced transformation by a combination of techniques, including transient absorption spectroscopy and Kelvin probe force microscopy. As a result, the application of the photochromic derivative offers improvements in photovoltaic performance and operational stability, highlighting the potential of dynamic photochromic strategies in perovskite photovoltaics.

Zn-TFSI₂ is introduced as a powerful p-dopant for spiro-MeOTAD in perovskite solar cells which not only outperforms Li-TFSI but also achieves outstanding long term stability.

Hybrid Perovskite Photovoltaics Photochromic materials enable dynamic stabilization of perovskite solar cells, such as during the simulated day-night cycles, which is the result of their reversible transformation in response to light, setting the stage for smart nature-inspired photovoltaic systems and technologies in the future. More details can be found in article number 2420143 by Jovana V. Milić and co-workers.

The application of perovskite photovoltaics is hampered by issues related to the operational stability upon exposure to external stimuli, such as voltage bias and light. The dynamic control of the properties of perovskite materials in response to light could ensure the durability of perovskite solar cells, which is especially critical at the interface with charge-extraction layers. We have applied a functionalized photochromic material based on spiro-indoline naphthoxazine at the interface with hole-transport layers in the corresponding perovskite solar cells with the aim of stabilizing them in response to voltage bias and light. We demonstrate photoinduced transformation by a combination of techniques, including transient absorption spectroscopy and Kelvin probe force microscopy. As a result, the application of the photochromic derivative offers improvements in photovoltaic performance and operational stability, highlighting the potential of dynamic photochromic strategies in perovskite photovoltaics.

Zn-TFSI₂ is introduced as a powerful p-dopant for spiro-MeOTAD in perovskite solar cells which not only outperforms Li-TFSI but also achieves outstanding long term stability.

All of the cations currently used in perovskite solar cells abide by the tolerance factor for incorporation into the lattice. We show that the small and oxidation-stable rubidium cation (Rb⁺) can be embedded into a "cation cascade" to create perovskite materials with excellent material properties. We achieved stabilized efficiencies of up to 21.6% (average value, 20.2%) on small areas (and a stabilized 19.0% on a cell 0.5 square centimeters in area) as well as an electroluminescence of 3.8%. The open-circuit voltage of 1.24 volts at a band gap of 1.63 electron volts leads to a loss in potential of 0.39 volts, versus 0.4 volts for commercial silicon cells. Polymer-coated cells maintained 95% of their initial performance at 85°C for 500 hours under full illumination and maximum power point tracking.

Abstract Perovskite solar cells (PSCs) have emerged as promising photovoltaic technologies due to their rapid increase in power conversion efficiency (PCE), now exceeding 26%. However, their long‐term operational instability, especially under thermal, moisture, and illumination stress, remains a major barrier to commercialization. This review summarizes recent advances in interface and electrode engineering strategies aimed at simultaneously improving the stability and efficiency of PSCs. In particular, charge transport layer optimization is emphasized, including the use of dopant‐free polymers, bilayer structures, and inorganic materials, as well as interfacial passivation approaches. Furthermore, emerging electrode technologies, such as carbon‐based electrodes and hybrid metal–carbon architectures, which address issues of metal ion migration, corrosion, and interfacial degradation, are explored. Interfacial modifiers, molecular passivators, and dimensional control strategies are also reviewed for their role in enhancing charge extraction and suppressing recombination. Through a comprehensive discussion of these materials and device‐level innovations, insight is provided into scalable pathways for fabricating stable and high‐performance PSCs suitable for real‐world applications.

Interface engineering is vital for optimizing charge transport, stability, and overall efficiency in perovskite solar cells. In this work, two novel fluorinated bathocuproine (BCP) derivatives, BCP-m2F and BCP-m4F, are introduced, featuring site-selective monofluorination at the terminal phenyl rings. Compared to the previously reported BCP-m1, which incorporates aryl substitution for improved planarity and charge transport, these new derivatives leverage fluorination to further tailor the electronic structure and interfacial behavior. The energy-level modulation by fluorination plays only a minor role; however, fluorination significantly enhances device stability through stronger binding with C₆₀ and a pronounced surface passivation effect. Experimentally, BCP-m4F demonstrates superior film uniformity and conductivity compared to BCP-m2F. Time-resolved photoluminescence, J-V analysis, contact angle measurements, and damp heat stability test (ISOS-D3) show improved charge extraction, reduced trap-assisted recombination, increased hydrophobicity, and enhanced thermal and moisture stability, respectively. Notably, a device employing BCP-m4F exhibits minimal open-circuit voltage loss under low-light conditions, highlighting its suitability for indoor or diffuse-light applications. These findings underscore the potential of combining rational backbone design with targeted fluorination to achieve multifunctional interlayers that enhance performance and reliability in next-generation perovskite solar cells.

Hybrid organic–inorganic layered (2D) halide perovskites have demonstrated advantages in improving the performance and stability of perovskite solar cells, and there is an ongoing interest in tailoring organic cations for their application in photovoltaics. We apply tailored molecular systems based on perfluorinated benzylammonium (F-BNA) and 1,4-phenylenedimethylammonium (F-PDMA) cations, forming Ruddlesden–Popper and Dion–Jacobson perovskite phases, respectively, at the interface with 3D perovskite layers in conventional n–i–p perovskite solar cells. The characteristics of 2D/3D perovskite phases are investigated through a combination of techniques including X-ray diffraction, UV–vis absorption, and photoluminescence spectroscopy. We demonstrate the beneficial effects of perfluoroarene perovskite phases in improving the stability and performance toward advancing photovoltaics.

In this work, the CuI thin film is introduced as an alternative back contact layer (BCL) to the expensive Au BCL for the Cu 2 O photocathodes. It is fabricated by a solution process using CuI precursor solution, dissolving CuI powders in acetonitrile. The thickness of CuI BCL is optimized by controlling the concentration of CuI precursor solution. As a result, the Cu 2 O photocathodes based on the CuI BCL with the optimal thickness (approximately 6.4 nm) show a comparable photoelectrochemical performance compared to the Cu 2 O photocathodes based on the traditional Au BCL. The solution‐processed CuI thin film properly works as a BCL for the Cu 2 O photocathodes by allowing the effective hole transport from Cu 2 O to the back contact and suppressing the hole–electron recombination at the back contact via the large conduction band offset at the CuI/Cu 2 O interface. This provides a novel and promising approach to develop the photocathode with entirely low‐cost materials for solar water splitting.