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A widely used component of high-efficiency perovskite solar cells (PSCs) is the molecular hole-transport material (HTM) spiro-OMeTAD. This organic solid needs to be p-doped to acquire sufficient hole conductivity. However, the conventional doping method using LiTFSI in the air is slow, sensitive to the environment, and may lead to the deterioration of the PSCs by unintended oxidation or dopant migration. It is thus highly desirable to develop fast doping approaches that avoid exposing the PSC to ambient air and easy-to-move dopant ions. We report here that light absorption by spiro-OMeTAD itself triggers redox photochemistry that has so far been ignored. Strikingly, we found that Y(III) or La(III)-tBP complexes catalyze the symmetry-breaking charge separation of photo-excited spiro-OMeTAD, resulting in the efficient p-doping of the HTM. Using this photo-redox process, we realize PSCs with superior stability over cells using conventional doping that show no degradation under continuous illumination over 1,000 h.

Optimized power system planning and operation are core to delivering a low-cost and high-reliability transition path to net-zero carbon emissions. The major technological changes associated with net zero, including the rapid adoption of renewables, electrification of transport and heating, and system-wide digitalization, each increase the scope for optimization to create value, but at the cost of greater computational complexity. Although power system optimization problems are now posing challenges for even the largest exa-scale supercomputers, a new avenue for progress has been opened by recent breakthroughs in quantum computing. Quantum computing offers a fundamentally new computational infrastructure with different capabilities and trade-offs and is reaching a level of maturity where, for the first time, a practical advantage over classical computing is available for specific applications. In this review, we identify significant and wide-ranging opportunities for quantum computing to offer value for power system optimization. In addition to reviewing the latest work on quantum computing for simulation-based and combinatorial power system optimization applications, we also review state-of-the-art theoretical work on quantum convex optimization and machine learning and map this to power system optimization applications where quantum computing is underexplored. Based on our review, we analyze challenges for industry implementation and scale-up and propose directions for future research.

Artificial intelligence (AI) has emerged as a tool for discovering and optimizing novel battery materials. However, the adoption of AI in battery cathode representation and discovery is still limited due to the complexity of optimizing multiple performance properties and the scarcity of high-fidelity data. We present a machine learning model (DRXNet) for battery informatics and demonstrate the application in the discovery and optimization of disordered rocksalt (DRX) cathode materials. We have compiled the electrochemistry data of DRX cathodes over the past 5 years, resulting in a dataset of more than 19,000 discharge voltage profiles on diverse chemistries spanning 14 different metal species. Learning from this extensive dataset, our DRXNet model can capture critical features in the cycling curves of DRX cathodes under various conditions. Our approach offers a data-driven solution to facilitate the rapid identification of novel cathode materials, accelerating the development of next-generation batteries for carbon neutralization.

Perovskite-silicon (Si) tandem solar cells are the most prominent contenders to succeed single-junction Si cells that dominate the market today. Yet, to justify the added cost of inserting a perovskite cell on top of Si, these devices should first exhibit sufficiently high power conversion efficiencies (PCEs). Here, we present two key developments with a synergetic effect that boost the PCEs of our tandem devices with front-side flat Si wafers—the use of 2,3,4,5,6-pentafluorobenzylphosphonic acid (pFBPA) in the perovskite precursor ink that suppresses recombination near the perovskite/C₆₀ interface and the use of SiO₂ nanoparticles under the perovskite film that suppresses the enhanced number of pinholes and shunts introduced by pFBPA, while also allowing reliable use of Me-4PACz as a hole transport layer. Integrating these developments in an optically and electrically optimized tandem device (e.g., with a durable Si cell), reproducible PCEs of 30 ± 1%, and a certified maximum of 30.9% are achieved.

Market liberalization and affordable distributed technologies leads to energy systems with “long-tail” characteristics. The emerging system is fragmented and dynamic, composed of numerous assets and multiple players with different motivations and capabilities. The long tail offers benefits for the environment, energy security, and consumers, while also introducing new regulatory challenges and safety concerns. This perspective describes the characteristics of the evolving long-tail system and highlights potential positive and negative impacts on the environment, society, and energy security, considering regulatory and governance gaps.

Yalun Li leads a research team in battery fast charging and swapping and vehicle-grid integration systems at Tsinghua University. He earned his PhD in power engineering from Tsinghua University, with his doctoral dissertation awarded by the China Society of Automotive Engineers. He is selected for China National Postdoctoral Program for Innovative Talents and serves as a youth editorial member for eTransportation.

Feiqin Zhu is a research associate at Brookhaven National Laboratory, researching transportation and power systems and specializing in energy-infrastructure planning for electric vehicles.

Liguo Li is the secretary-general of the China Battery Swapping Heavy-Duty Truck Alliance and leads a key R&D program on battery swapping trucks.

Minggao Ouyang is a professor at Tsinghua University and a member of the Chinese Academy of Sciences. He focuses on electrochemical energy storage, hydrogen energy, and smart energy systems. He has served as the chief scientist of China’s New Energy Vehicle Project and the China-US Clean Vehicle Research Alliance. He was honored with the IEEE Transportation Technologies Award.

The commercialization of organic solar cells (OSCs) encompasses overcoming hurdles related to efficiency, stability, cost, and complexity of device fabrication techniques. The elaborate sequential deposition (SD) process for fabricating charge-transport and photoactive layers stands out as a critical challenge. In this study, we synthesized a series of self-assembling hole-transport molecules, namely, BPC-M, BPC-Ph, and BPC-F, to investigate the mechanism within self-assembling deposition (SAD). The synthesized molecules in SAD-processed cells exhibit significantly varied photovoltaic performance. Notably, BPC-M achieves a superior power conversion efficiency of 19.3% in SAD-processed PBDB-TF:eC9 cells. However, cells incorporating BPC-F show significant performance degradation. It is demonstrated that the thermodynamic forces driven by surface free energy, coupled with intermolecular interactions, are pivotal in dictating the self-assembly efficiency. This determines the quality of the self-assembled layer and the residual molecule in the active layer. This study simplifies OSC fabrication and offers a promising approach for the industrialization of OSCs.

Improving the performance of triboelectric nanogenerators (TENGs) is crucial for their practical application. Conventional methods have inherent limitations, including complexity, increased costs, and restricted applicability to various types of TENGs. Here, we propose a novel triboelectrification enhancement effect (TEE) to efficiently enhance the triboelectric charges of tribo-materials, achieving a remarkable 14.8-fold improvement in charge generation and a staggering 173.2-fold increase in output energy. The TEE offers a universal solution to enhance the performance of all types of TENGs. A contact-separation mode TENG using the TEE achieves ultrahigh transferred charge and power density of 2.2 μC and 20.6 W/m³, respectively. After implementing power management, the TENG produces a pulse direct current output of 10.2 mA. Importantly, the prototype can power buoys and wave warning systems with wireless transmission by harvesting energy from both the water surface and underwater. This work provides a universal and simple method to boost the performance of TENGs.

Here, we first visualize the achievable global efficiency for single-junction crystalline silicon cells and demonstrate how different regional markets have radically varied requirements for Si wafer thickness and injection level. Our findings showed that 219 g/kW of polysilicon can be conserved while producing slightly more electricity when c- Si cells are manufactured based on the global geographical market instead of standard test conditions. Then, we investigate the bifacial silicon cell and show that its optimal wafer thickness should be 1.67–2.89 times thicker than its monofacial counterpart, depending on the geographical region. Further, we study a double-junction two-terminal Si-based cell, reevaluate its theoretical limit as 42.8%, and illustrate that globally, tandem cells’ efficiency will only be slightly decreased when significantly reducing the bottom cell Si wafer thickness (−0.3%/mm). The outcomes of this study offer a blueprint to strategically design solar cells for target geographic markets, ensuring the conservation of substantial polysilicon volumes.

Electrochemical CO₂ reduction on Cu-based catalysts is a promising technique to convert CO₂ to high-value C₂ and C₃ feedstocks. High carbon efficiency can be achieved in acidic electrolytes, but Cu-based catalysts show suppressed activity toward C₂₊ formation in acidic conditions. Acid removes the oxygen-containing species on Cu, which are necessary for C–C coupling. In this work, a gas diffusion electrode (GDE)/Cu/Ni-N-C tandem configuration, in which Ni-N-C served as a CO₂-to-CO catalyst, expressed a 5-time enhancement of C₂₊ formation activity compared with GDE/Cu. Electrochemical measurements and finite element simulations indicate the improved C₂₊ formation activity was due to the elevated local pH rather than the increased CO concentration in the Cu catalyst layer. The major function of the CO-formation catalyst in the tandem system working in an acidic condition is to modulate the local pH near the Cu catalyst instead of producing CO intermediate for Cu.