Explore the vast range of titles available.

Perovskite solar cells with an inverted architecture provide a key pathway for commercializing this emerging photovoltaic technology because of the better power conversion efficiency and operational stability compared with the normal device structure. Specifically, power conversion efficiencies of the inverted perovskite solar cells have exceeded 25% owing to the development of improved self-assembled molecules 1 – 5 and passivation strategies 6 – 8 . However, poor wettability and agglomeration of self-assembled molecules 9 – 12 cause interfacial losses, impeding further improvement in the power conversion efficiency and stability. Here we report a molecular hybrid at the buried interface in inverted perovskite solar cells that co-assembled the popular self-assembled molecule [4-(3,6-dimethyl-9 H -carbazol-9-yl)butyl]phosphonic acid (Me-4PACz) with the multiple aromatic carboxylic acid 4,4′,4″-nitrilotribenzoic acid (NA) to improve the heterojunction interface. The molecular hybrid of Me-4PACz with NA could substantially improve the interfacial characteristics. The resulting inverted perovskite solar cells demonstrated a record certified steady-state efficiency of 26.54%. Crucially, this strategy aligns seamlessly with large-scale manufacturing, achieving one of the highest certified power conversion efficiencies for inverted mini-modules at 22.74% (aperture area 11.1 cm 2 ). Our device also maintained 96.1% of its initial power conversion efficiency after more than 2,400 h of 1-sun operation in ambient air. High efficiency in perovskite solar cells is achieved by using a molecular hybrid of a self-assembled monolayer with nitrilotribenzoic acid.

Perovskite‐organic tandem solar cells (TSCs) have emerged as a groundbreaking technology in the realm of photovoltaics, showcasing remarkable enhancements in efficiency and significant potential for practical applications. Perovskite‐organic TSCs also exhibit facile fabrication surpassing that of all‐perovskite or all‐organic TSCs, attributing to the advantageous utilization of orthogonal solvents enabling sequential solution process for each subcell. The perovskite‐organic TSCs capitalize on the complementary light absorption characteristics of perovskite and organic materials. There is a promising prospect of achieving further enhanced power conversion efficiencies by covering a broad range of the solar spectrum with optimized perovskite absorber, organic semiconductors as well as the interconnecting layer's optical and electrical properties. This review comprehensively analyzes the recent advancements in perovskite‐organic TSCs, highlighting the synergistic effects of combining perovskite with a low open‐circuit voltage deficit, organic materials with broader light absorption, and interconnecting layers with reduced optical and electrical loss. Meanwhile, the underlying device architecture design, regulation strategies, and key challenges facing the high performance of the perovskite‐organic TSCs are also discussed. Perovskite‐organic tandem solar cells (TSCs) have exhibited significant achievements in the interconnecting layers, perovskite, and organic solar cells, reducing the performance gap between perovskite‐perovskite and perovskite‐organic TSCs. Herein, we comprehensively analyze and discuss the recent advancements in perovskite‐organic TSCs, highlighting the synergistic effects and development of perovskite, organic, and interconnecting layers.

The upscaling of perovskite solar cells to module scale and long-term stability have been recognized as the most important challenges for the commercialization of this emerging photovoltaic technology. In a perovskite solar module, each interface within the device contributes to the efficiency and stability of the module. Here, we employed a holistic interface stabilization strategy by modifying all the relevant layers and interfaces, namely the perovskite layer, charge transporting layers and device encapsulation, to improve the efficiency and stability of perovskite solar modules. The treatments were selected for their compatibility with low-temperature scalable processing and the module scribing steps. Our unencapsulated perovskite solar modules achieved a reverse-scan efficiency of 16.6% for a designated area of 22.4 cm 2 . The encapsulated perovskite solar modules, which show efficiencies similar to the unencapsulated one, retained approximately 86% of the initial performance after continuous operation for 2,000 h under AM1.5G light illumination, which translates into a T 90 lifetime (the time over which the device efficiency reduces to 90% of its initial value) of 1,570 h and an estimated T 80 lifetime (the time over which the device efficiency reduces to 80% of its initial value) of 2,680 h. The upscaling of layer treatments and processing that afford high efficiency and stability in small-area perovskite solar cells remains challenging. Liu et al. show how the efficiency and stability of perovskite modules can be improved using an integrated approach to interface and layer engineering.

In recent years, the major factors that determine commercialization of perovskite photovoltaic technology have been shifting from solar cell performance to stability, reproducibility, device upscaling and the prevention of lead (Pb) leakage from the module over the device service life. Here we simulate a realistic scenario in which perovskite modules with different encapsulation methods are mechanically damaged by a hail impact (modified FM 44787 standard) and quantitatively measure the Pb leakage rates under a variety of weather conditions. We demonstrate that the encapsulation method based on an epoxy resin reduces the Pb leakage rate by a factor of 375 compared with the encapsulation method based on a glass cover with an ultraviolet-cured resin at the module edges. The greater Pb leakage reduction of the epoxy resin encapsulation is associated with its optimal self-healing characteristics under the operating conditions and with its increased mechanical strength. These findings strongly suggest that perovskite photovoltaic products can be deployed with minimal Pb leakage if appropriate encapsulation is employed. Lead leakage from damaged perovskite solar cells poses a challenge to the deployment of such technology. Here, Jiang, Qiu and co-workers quantify lead leakage caused by a simulated hail impact under a number of weather conditions and show that self-healing encapsulations can effectively reduce it.

Tandem photovoltaics hold great potential to surpass the efficiency limit of single-junction solar cells. Detrimental structural defects and chemical reactions at buried interfaces of subcells considerably impede the performance of integrated tandems. Here, we devise a mercapto-functionalized mesoporous silica layer as a superstructure at the buried interface to modulate the crystallisation, eliminate nanovoids, passivate defects, and suppress the oxidation of Sn(II) in the tin–lead perovskite films, contributing substantially to reduce charge carrier losses and improve stability in positive-intrinsic-negative structured devices. Consequently, the tin–lead perovskite single-junction cells show efficiency values of up to 23.7% with the best open-circuit voltage of 0.89 V. With the enhanced subcells, our double-junction tandems show efficiency values of 29.6% (certified 29.5% and steady-state 28.7%) and 24.7% on solar cells and 11.3 cm 2 mini-modules, respectively. Encapsulated tandems maintain 90% of initial efficiency after 445 h of maximum power point tracking under simulated 1-sun illumination. It is generally more difficult to modify the buried interfaces compared to top interfaces in tin-lead perovskite subcells. Here, the authors employ a mercapto-functionalized mesoporous silica layer as a superstructure, realizing maximum efficiency of 29.6% for double-junction tandem solar cells.

Besides high efficiency, the stability and reproducibility of perovskite solar cells (PSCs) are also key for their commercialization. Herein, we report a simple perovskite formation method to fabricate perovskite films with thickness over 1 μm in ambient condition on the basis of the fast gas−solid reaction of chlorine-incorporated hydrogen lead triiodide and methylamine gas. The resultant thick and smooth chlorine-incorporated perovskite films exhibit full coverage, improved crystallinity, low surface roughness and low thickness variation. The resultant PSCs achieve an average power conversion efficiency of 19.1 ± 0.4% with good reproducibility. Meanwhile, this method enables an active area efficiency of 15.3% for 5 cm × 5 cm solar modules. The un-encapsulated PSCs exhibit an excellent T 80 lifetime exceeding 1600 h under continuous operation conditions in dry nitrogen environment. Perovskite solar cells often suffer from poor uniformity and reproducibility especially in case of large area devices. Here Liu et al. developed a gas−solid reaction method that enables facile fabrication of over 1 µm thick perovskite films for solar modules with high efficiency, stability and reproducibility.

Stability and scalability are essential and urgent requirements for the commercialization of perovskite solar cells (PSCs), which are retarded by the non‐ideal interface leading to non‐radiative recombination and degradation. Extensive efforts are devoted to reducing the defects at the perovskite surface. However, the effects of the buried interface on the degradation and non‐radiative recombination need to be further investigated. Herein, an omnibearing strategy to modify buried and top surfaces of perovskite film to reduce interfacial defects, by incorporating aluminum oxide (Al2O3) as a dielectric layer and growth scaffolds (buried surface) and phenethylammonium bromide as a passivation layer (buried and top surfaces), is demonstrated. Consequently, the open‐circuit voltage is extensively boosted from 1.02 to 1.14 V with the incorporation of Al2O3 filling the voids between grains, resulting in dense morphology of buried interface and reduced recombination centers. Finally, the impressive efficiencies of 23.1% (0.1 cm2) and 22.4% (1 cm2) are achieved with superior stability, which remain 96% (0.1 cm2) and 89% (1 cm2) of its initial performance after 1200 (0.1 cm2) and 2500 h (1 cm2) illumination, respectively. The dual modification provides a universal method to reduce interfacial defects, revealing a promising prospect in developing high‐performance PSCs and modules. The aluminum oxide (Al2O3) nanoparticles are imbedded into the buried interface, which fills the voids and grain boundaries of perovskite, leading to compact morphology and reduced dangling bonds and defects. The suppressed trap‐assisted recombination, better energy alignment, and decreased J–V hysteresis in the modified device with Al2O3 nanoparticles and phenethylammonium bromide contribute to a significant increase in voltage and stability.

Wide-bandgap (WBG) perovskites with bandgaps exceeding 1.8 eV are suitable for perovskite/organic or multi-junction tandem solar cell (TSC) applications. However, their complex components easily induce hardly controlled phase heterogeneity and defects during the crystallization process. Herein, we propose a multifunctional additive, DL-methionine methylsulfonium chloride, with a unique combination of functional groups to regulate the crystallization thermodynamics and passivate defects of WBG perovskites. Our comprehensive experimental and computational results reveal that the additive synergistically promotes the nucleation kinetics and improves phase homogeneity during the crystallization process, thereby achieving uniform and low-defect perovskite films, significantly suppressing the non-radiative recombination and phase segregation. Consequently, the single-junction 1.83 eV-WBG perovskite solar cells demonstrate a champion power conversion efficiency (PCE) of 20.4% and notably enhanced operational stability. Furthermore, impressive PCEs of 26.0% and 22.1% are achieved for rigid and flexible perovskite/organic TSCs, respectively, showing great promise for pursuing flexible tandem applications. Defect formation and phase instability remain critical challenges for perovskite/organic tandem solar cells. Jiang et al. address this by designing an additive to modulate the crystallization thermodynamics of wide-bandgap perovskite, achieving a record efficiency of 22.1% in a flexible cell.

Perovskite/organic tandem solar cells are a promising strategy to surpass the efficiency limits of single-junction devices, yet their performance is restricted by recombination losses in the organic subcells. Here, we investigate these losses by tracking film evolution from the very initial stage of organic film formation. We strategically manipulated donor and acceptor ratios to modulate film growth characteristics, while employing in situ techniques to monitor the real-time crystallization dynamics. Our research findings underscore that the variance in donor content within the organic blend exerts a fine-tuning effect on the solution-to-solid transformation process. When the donor content is inadequate, the acceptor molecules tend to aggregate, disrupting molecular packing and lowering crystallinity. These morphological changes hinder exciton dissociation, thereby leading to charge recombination and deteriorating overall device performance. Optimizing film morphology and crystallization reduces recombination losses, enabling perovskite/organic tandem solar cells with a record 26.42% power conversion efficiency. The efficiency of perovskite/organic tandem devices is impeded by recombination losses that occur within the organic subcells. Here, the authors monitor film growth and crystallization dynamics in real-time and mitigate exciton recombination losses, achieving maximum device efficiency of 26.42%.

Flexible sensors have attracted significant attention as they could be directly attached to/implanted into the body or incorporated into textiles to monitor human activities and give feedbacks for healthcare. A typical fabrication method is the direct use of intrinsically flexible active materials such as carbon nanotubes (CNTs). CNTs are generally assembled into aligned structures to extend their remarkable chemical, mechanical, and electrical properties to macroscopic scale to afford high sensing performances. In this review, we present the recent advance of CNT assemblies as electrodes or functional materials for flexible sensors. The realizations of aligned CNTs are firstly investigated. A variety of flexible sensors based on the aligned CNTs are then carefully explored, with an emphasis on understanding the working mechanism for their high sensing properties. The main attention is later paid to comparing two main categories of flexible sensors with fiber and film shapes. The remaining challenges are finally highlighted to offer some insights for future study. The recent advance of flexible sensors based on carbon nanotube assemblies as electrodes or functional materials has been carefully discussed, with an emphasis on understanding the working mechanism for their high sensing properties. The remaining challenges are finally highlighted to offer some insights for future study.